By Lauren Fox

CNN

WASHINGTON (CNN) -- With a new week before them, Republican leaders continue the hunt for the 216 votes they need to repeal and replace Obamacare, a kind of Groundhog Day exercise that has consumed the early days of Donald Trump's presidency, the GOP's agenda and irritated some who fear the process has gone off the rails.

But as hard as it is, leaders know they can't simply abandon their effort now.

"I hope we keep going. I don't think we can stop," said Rep. Brett Guthrie, a Republican who serves on the House's Energy and Commerce Committee told CNN last week.

Trump said Sunday the White House is pushing forward, and that the GOP plan "guarantees" coverage for Americans with pre-existing conditions.

"Pre-existing conditions are in the bill. And I mandate it. I said, 'Has to be,'" Trump said on CBS's "Face the Nation" Sunday.

Pressed further, Trump said that "we actually have a clause that guarantees" coverage for those with pre-existing conditions. Trump also said the health care legislation is "changing."

Unlike the mandate under Obamacare, however, under the GOP bill insurers could charge them higher rates than others in the plan if they allow their coverage to lapse.

Republicans might seem stuck in a never ending cycle of trying to please the moderate and conservative wings of their party but pressure from the White House to deliver a legislative win for Trump is real. Also real: the repeated pledges to their constituents over the past seven years to repeal and replace Obamacare if given the chance.

There is still no official timeline to put the health care repeal and replace bill on the floor, and leadership aides are unequivocal that the bill will move only once leadership knows they have the 216 votes needed. GOP leaders continued to discuss the effort with members over the weekend, but some question what makes this effort different from the previous failed attempts.

"I'm not terribly optimistic right now," Rep. Charlie Dent, R-Pennsylvania, told CNN's New Day. "I think we need to change the paradigm."

Last week Republicans seemed to reach a major breakthrough on health care.

A new amendment sponsored by moderate leader Rep. Tom MacArthur of New Jersey gave states the ability to opt out of more Obamacare regulations. The amendment was also enough to finally bring the conservative House Freedom Caucus on board.

But the amendment, which experts noted could drive up the cost of insurance for older Americans and those with pre-existing conditions, spooked moderates and left some -- who had been supportive of the legislation before -- scrambling to publicly voice their discontentment. All of a sudden, it was moderates in the hot seat.

It seemed that even though leadership may have gained upwards of 30 new votes from the Freedom Caucus, they were suffering significant enough losses from the other side of the party that they still couldn't bring a bill up to the floor for a vote in order to mark Trump's first 100 days in office. A CNN whip count had recorded 16 Republicans as nos. The GOP can only afford to lose 21 depending on attendance.

This week, leadership's focus remains trying to help those moderates get comfortable with the new MacArthur amendment. Leadership aides emphasize that there isn't much room to change the proposal at this point, but many deputy whips are trying to get members to keep the process in perspective.

"You remind them there is a United States Senate, and it will change things. What we send over there isn't going over there on stone tablets," said Rep. Tom Cole, R-Oklahoma.

After last week though many moderates are frustrated with the process. Some say they see their party making the same kind of mistakes Republicans criticized Democrats for making back in 2010.

"We didn't learn anything from their mistakes," said Rep. Mark Amodei, a moderate Republican from Nevada told CNN. "We learned nothing from their mistakes."

As to promises the bill will be changed once it's in the Senate?

"Seriously, you want me to go back and tell the people in my fourth of Nevada 'the Senate will make it better?'" Amodei said. "What the hell?"

CNN's Eric Bradner contributed to this report.