By David Shortell and Eli Watkins, CNN

(CNN) -- As President Donald Trump ramps up his criticism of NFL National Anthem protests, his attorney general on Tuesday waded into a different culture war with an address to law students about free speech on college campuses.

Attorney General Jeff Sessions warned of people seeking to block open discourse on campuses and said he did not see a contradiction between that robust defense of speech with Trump's sustained criticism of protests held by professional athletes.

"The President has free speech rights, too," Sessions said, following a speech at Georgetown University Law Center in Washington.

Sessions said he agrees with Trump in opposing the protests.

"It is a big mistake to protest in that fashion," Sessions said, adding, "I would condemn their actions."

He argued the players were, in effect, "denigrating" symbols of the US, and noted that while players wouldn't be subject to prosecution, they could expect condemnation for taking "provocative" actions.

Sessions, after a speech calling on universities to push back against those who would seek to block controversial speakers on campus, said it is "up to the owners" to decide what they would allow on the football fields.

"Not a contradiction there," Sessions said.

During the question-and-answer portion, Sessions was also asked about the time Senate Majority Leader Mitch McConnell cut off Democratic Massachusetts Sen. Elizabeth Warren from reading a letter by Coretta Scott King to oppose Sessions' nomination. The attorney general said he believed Warren had the right to read the letter and defended the strength of debate in the US Senate.

"She certainly had the right to criticize my nomination," Sessions said. "And I think she really had the right to read the letter that she was blocked, or at least temporarily blocked, from reading."

He added, "In general, the Senate is one of the most open forums in the history of the world" and suggested caution before constricting any senator's speech.

'Shelter for fragile egos'

In his speech, Sessions lamented American universities "transforming into an echo chamber of political correctness and homogenous thought, a shelter for fragile egos."

He called college administrators' giving into protesters' demands to rescind invitations for some speakers as giving into "the heckler's veto."

"In other words, the school favors the heckler's disruptive tactics over the speaker's First Amendment rights," Sessions said.

He announced the Justice Department would submit a statement of interest in a campus free speech lawsuit and said he anticipated more such moves soon.

Protesters, including faculty members, lined up outside the attorney general's event at Georgetown, at one point dropping to one knee, a reference to the growing NFL National Anthem protests.

Protestors taped their mouths and held signs, with one saying "Sessions is afraid of questions" and another reading "why do you silence dissent but applaud hate speech?"

A row of silent protesters in black shirts stood up in the room where Sessions delivered his speech. They placed tape across their mouths and sat down.

During a series of pre-submitted questions, Sessions was asked about the protests taking place. He responded that he respected everyone's views and their expression in an appropriate fashion, and again called on universities to "push back" against those who would seek to block speech.

"We celebrate the diversity of opinion," Sessions said.

Violent clashes in free speech debates

The debate Sessions entered has, in recent months, become a violent one.

In February, on the campus of the University of California, Berkeley, black-clad agitators smashed windows and hurled Molotov cocktails ahead of a planned appearance by far-right controversialist Milo Yiannopoulos. At Middlebury College in Vermont in March, protests outside the speech of a conservative political scientist devolved into a shoving match that left one professor hospitalized.

Flashpoints around hot-button speakers, alongside a trend of trigger warnings and safe spaces, have fueled reputations that places of higher education are hostile to the First Amendment. More US adults surveyed by Gallup last year thought that Americans' ability to exercise their free speech rights is weaker today than 20 years ago (40%), than those who thought it was stronger (31%).

Sessions has a strong interest in First Amendment protection and has discussed publicly remarking on university turbulence for months, according to a source familiar with the speech.

Students and faculty members of Georgetown's law school said ahead of the event that they planned on protesting the attorney general's speech.

"I find it hypocritical for a member of the Trump administration to act as a champion for free speech while the President has consistently mocked and insulted those trying to exercise the very same rights," said Richard Hand, a third-year law student at the university.

"I think we understand those things without him having to tell us that, " added third-year student Spencer McManus. "I don't deny that he has the right to say what he wants and what he thinks -- I certainly believe that very strongly. It's the irony of him coming here."

The law students, who helped organize a rally, point towards Trump's recent fight with NFL players who have protested civil rights abuses during National Anthem performances and the Justice Department's decision to prosecute a woman who laughed at Sessions during his confirmation hearing as examples of the hypocrisy. The woman, Desiree Fairooz, faces a November trial over charges of unlawful conduct after she rejected a plea deal offered by prosecutors earlier this year.

Sessions has regularly faced small groups of protestors outside his speeches around the country, many denouncing his views on criminal justice and policing issues.

A Georgetown Law spokeswoman said Monday night that the campus has "designated protest areas for high-profile speaker events" and that entry into the law school buildings are restricted to members of the school community and their invited guests.

"We are committed to upholding the values of academic freedom and serving as a forum for the free exchange of ideas, even when those ideas may be difficult, controversial or objectionable to some," spokeswoman Tanya Weinberg said.

Some on Monday also criticized the university's ticketing of the address, which is only open to a small group of students that have in the past signed up to attend at least one event held by its host organization. The group, the Georgetown Center for the Constitution, says it hosts programs to examine "how best to remain faithful to the Constitution's text."

Professor Randy Barnett, the right-leaning law professor who leads the group and is slated to speak Tuesday after Sessions, also invited students from his classes, Weinberg said. Both policies, she said, are in line with university policy "given limited capacity."

Sessions was met before his Georgetown appearance also with a statement signed by 44 members of the university law school faculty rebuking his remarks and saying that "a man who fails to recognize paradigmatic violations of the First Amendment is a poor choice to speak about free speech on campuses."