By Zachary Cohen and Phil Mattingly, CNN

(CNN) -- Shortly before 1 p.m. on Tuesday, having just received a classified briefing from the director of the CIA in the basement of the Capitol, two Republican senators stepped to a crowd of cameras and reporters. With a few pointed words, the pair blew up the Trump administration's efforts to minimize the political damage stemming from journalist Jamal Khashoggi's murder.

"There's not a smoking gun, there's a smoking saw," Sen. Lindsey Graham said, referencing allegations that Saudi operatives dismembered Khashoggi's body after killing him in October inside the Saudi embassy in Turkey.

The South Carolina Republican took aim at the White House's insistence that U.S. intelligence agencies had no direct evidence linking the murder to Saudi Arabia's powerful Crown Prince Mohammed bin Salman, known as MBS, even though it was carried out by members of his inner circle. "You have to be willfully blind not to come to the conclusion that this was orchestrated and organized by people under the command of MBS."

Nearby, Republican Sen. Bob Corker told reporters there was "zero question in my mind" that MBS was behind the killing. "If he was in front of a jury," said the Tennessee Republican, "he would be convicted in 30 minutes, guilty."

From the early leaks of its gruesome details to President Donald Trump's muted responses to Tuesday's full-throated rebuke from Republican senators, the Khashoggi murder has been an exercise in political mismanagement and discord. What could have been an opportunity to craft a unified American response has devolved into a political standoff, laying bare divisions among the White House, the intelligence community and Congress.

For weeks the Trump administration has tried to separate the crown prince from the horrific murder. It's also sought to frame the broader issue as a binary choice of either getting in line with its defense of Saudi Arabia or taking the risk of cutting off relations with one of America's closest partners in the Middle East. Even for national security hawks like Lindsey Graham, who is among the President's closest allies in Congress and is himself a long-time supporter of Saudi Arabia, that has been a bridge too far.

The Khashoggi murder has also worsened the tension between the White House and Congress over America's support for Saudi Arabia's war in Yemen, which has turned into a full-blown humanitarian crisis, forcing an administration pushing for a cessation in the conflict -- and deeply opposed to congressional meddling on the issue -- onto its heels.

Interviews with more than a dozen U.S. lawmakers and intelligence officials reveal a deep frustration and anger over what many describe as the administration's bungled response, at home and abroad, to a searing murder that raises questions over the nature of America's alliance with the Saudis and US claims of moral leadership in the world.

Last week, in an attempt to contain the growing outrage, the White House dispatched its two most prominent Cabinet officials to Capitol Hill. But the visit by Secretary of State Mike Pompeo and Secretary of Defense Jim Mattis appeared to do more harm than good.

Rather than getting a direct brief from CIA director Gina Haspel, as many had requested, lawmakers got a limited version that emphasized a technical distinction that the CIA had no direct proof that MBS had ordered Khashoggi's murder, despite the fact that the CIA rarely includes direct proof in its assessments.

It didn't help that lawmakers woke up that morning to a hardline op-ed by Pompeo in the pages of the Wall Street Journal. In it, Pompeo criticized "the Capitol Hill caterwauling and media pile-on" the murder had elicited, and equated critics of the Saudis with supporters of President Barack Obama's Iran deal -- a sentiment that, according to one senior GOP aide, landed "like a lead balloon."

The frustration led to a bipartisan revolt for all to see, live on the floor of the US Senate. Minutes after Pompeo and Mattis left, a majority of senators, including 14 Republicans, voted to advance a resolution to curtail US support for Saudi Arabia's war in Yemen -- a resolution that had failed in March, and that Pompeo and Mattis had urged them to reject.

A week later, Graham landed his own op-ed in the Wall Street Journal, in which he defended Congress' right to oppose the administration in order to "safeguard the country's long-term interests, values and reputation."

"After all," Graham wrote, "someone's got to do it."

Leaks and infighting

For its part, the administration has condemned the murder and imposed sanctions on 17 individuals linked to it. At the same time, Trump and top administration officials have consistently cited the historic alliance between the two countries, and framed allegations of MBS's involvement as an attack that could threaten the relationship. It has rationalized that stance with what it claims is the lack of a final conclusion by the CIA on the question of whether MBS directed the murder.

But that rationale has deteriorated as a steady drip of details related to the CIA's assessment of the murder have painted an increasingly damning picture related to the crown prince's potential involvement.

Last month, the CIA delivered a report on the murder to lawmakers in the "Gang of Eight"-- the chairmen and top Democrats on the two Intelligence Committees and the four House and Senate party leaders. When details leaked, including that the CIA had determined with a high degree of confidence that MBS directed the killing, Trump and White House officials blamed the CIA for briefing too many people, according to several US officials. In turn, members of the intelligence community were angry over the way that Haspel was thrust into the middle of a political fight between the White House and Congress.

Last week as Pompeo and Mattis visited the Hill, Haspel's absence took center stage following lawmakers' claims that the White House blocked her from appearing. The CIA issued a rare on the record statement rebutting that, saying "the notion that anyone told Director Haspel not to attend today's briefing is false." And multiple US officials pointed out that her preference all along was to stay out of the spotlight.

While there is no indication that the administration told Haspel explicitly whether or not she could attend, several sources have noted that the White House had made clear, even if not directly to Haspel, that they did not want her there, and that she had little reason to push the issue as it would have only hurt her standing within the administration.

When a small group of senior senators responsible for direct oversight of the agency and its funding asker her to brief them, Haspel had no choice but to oblige. Her appearance drew sharp statements from lawmakers who compared her briefing favorably to what they'd gotten from Pompeo and Mattis. Corker told CNN Haspel delivered the "Most precise presentation I've ever heard in 12 years."

Distance from MBS

In the leadup to this week's brief, the President and his aides watched angrily as leaks continued to emerge showing the CIA has evidence that MBS and a top aide involved in Khashoggi's murder exchanged multiple messages around the time of the killing. The details of those messages however have not been revealed.

At the G20 summit in Argentina over the weekend, images of Russian President Vladimir Putin backslapping the young Saudi prince were met with a certain degree of satisfaction among Trump's aides -- the best illustration, in their minds, of what it might look like should Riyadh turn away from the United States and toward other, more repressive, regimes.

Trump's encounters with MBS at the G20 were purposely kept at a minimum. Advisers stacked the President's agenda with meetings, making little time for extended discussions with the crown prince. When the two did run across each other on the margins of a group meeting, there was little time for detailed talks. The discussion was cordial, one person familiar with it said, and not the type of direct confrontation that French President Emmanuel Macron employed when he ran across MBS at the summit.

Congress ignored

Animating much of the anger among lawmakers over the Khashoggi affair is the sense that they have been ignored throughout the process. According to interviews with more than a dozen senators and aides, at the heart of the split was the administration's refusal to budge when concerns were raised about the murder, as well as the growing crisis in Yemen. As many as 14 million Yemenis are suffering severe food shortages, aid agencies say, while an estimated 85,000 children under the age of 5 may have already died of starvation or disease, according to Save the Children.

Corker made clear he had no desire to support the resolution cutting off US military aid for Saudi operations in Yemen. For days he pleaded with the administration, privately and publicly, to change course. A statement. A more active policy response. Something to send a message to the young Saudi crown prince. But nothing came., so he voted to support the resolution even though he opposed its intent.

While Corker has frequently clashed with Trump, the administration's accommodating posture toward Saudi has turned even some of its strongest allies into critics. Sen. Todd Young is a prime example. An Indiana Republican and Naval Academy graduate, Young is known to be a staunch national security hawk -- and he said recently he "will take a backseat to no one as an Iran hawk" -- but for nearly two years he has made a primary focus the expanding humanitarian crisis in Yemen and pressuring the administration to change the conflict's trajectory.

He is also known to be press shy, avoiding hallway interviews with reporters and rarely weighing in on issues unless he has a specific point to make.

That changed shortly before Pompeo's briefing, when Young and an aide walked up to a group of reporters standing near a bank of cameras and said he wanted to make an on-camera statement. He ended up taking to the Senate floor instead, where he unleashed a blistering speech.

Young noted the administration, for months, had not taken seriously a statutory requirement to certify that the government of Saudi Arabia was taking steps to end the civil war in Yemen and the resulting humanitarian crisis. The certification the administration had sent — which was required by a measure Young had helped craft and push into law — "was not credible," he said on the floor. "Despite repeated requests for answers to our questions regarding Saudi Arabia and Yemen, we couldn't get responsive or timely answers from the administration."

Young then detailed a bipartisan follow-up letter, which asked the administration for clarifications about clear inconsistencies in its certification. It had been ignored until the day before Pompeo's briefing, when the administration, belatedly recognizing the trouble it was in on the Yemen resolution vote, finally replied. As to how it was received: "It was late, and it was unresponsive," Young said. He too would join Corker in supporting the Yemen measure he had previously opposed, he said.

What can Congress do?

While most of the roughly dozen senators who were briefed by Haspel said the US should issue a response punishing those involved in Khashoggi's murder, there is not yet consensus on what to do, or even if Congress has the bandwidth to pass anything with teeth. The Republican-led House has made clear it won't take up anything the Senate sends its way. There's less than a month to go on the current session of Congress, and of course, the President could veto any bill sent his way.

Wednesday night, Graham -- along with Sens. Marco Rubio, Dianne Feinstein, Ed Markey, Todd Young and Chris Coons -- introduced a strongly worded though non-binding resolution condemning the crown prince for a range of actions, including the crisis in Yemen, the blockade in Qatar, the jailing of dissidents and the killing of Khashoggi. The measure is a symbolic rebuke -- and could be added to a broader package targeting Saudi Arabia.

"Those who suggest we must sacrifice our principles for security will have neither," said Young, a Republican from Indiana.

Graham and Young, along with Sen. Bob Menendez of New Jersey, the top Democrat on the Foreign Relations panel, are pushing a separate bill to require mandatory sanctions on any individual responsible for the death of Khashoggi, which could include MBS. It also, among other provisions, would call for a total prohibition on sales of arms to Saudi Arabia that could be used for offensive purposes -- a potential flashpoint for a President who has repeatedly touted arm sales to the kingdom as he describes the US-Saudi relationship.

Discussions are ongoing about whether to go for an up or down vote on the Senate floor for the resolution curtailing US support for the war in Yemen, or whether to open the floor up to a potentially unruly amendment process. Corker is crafting an amendment that would directly address the Khashogi issue, and potentially separate it from Yemen. Senate aides say the process remains fluid, as meetings across Capitol Hill continue behind closed doors.

The real importance of congressional action, senators and aides involved in the efforts say, is the message it sends to the world, particularly as the parties negotiate in Sweden over a ceasefire. Pompeo has emphasized the importance of giving the warring parties in Yemen the space to reach a deal rather than piling on pressure from Congress. "The more support from you we get the better chance we have of ending the conflict and stopping the suffering that none of us are happy about."

The administration's efforts on that front haven't just been confined to Congress. CNN reported last month that the US had "slammed the brakes on" a United Nations Security Council resolution calling for a limited ceasefire and increased humanitarian aid in Yemen, over concerns about angering Saudi Arabia.

The White House's defense of Saudi -- and its explicit support for MBS -- shows no signs of abating, a calculation defined by the long-standing relationship and its value to countering foes like Iran. Recent weeks have shown that it is a stance, however firm, that could come at a cost. Already some of Capitol Hill's stalwart Trump supporters have broken with the President and his Cabinet on this issue. Graham, a Trump golfing partner and vocal supporter of the President and his top lieutenants, went so far as to accuse Pompeo and Mattis of willful ignorance. "I think the reason they don't draw the conclusion that (MBS) is complicit is because the administration doesn't want to go down that road."