Washington (CNN) Some Republicans seeking the White House blasted University of Missouri administrators for resigning in the wake of continued protests, while Democrats said they were standing with students and others looking to address what they say is structural racism.

"I think it's just disgusting. I think the two people who resigned are weak, ineffective people," Donald Trump said on Fox News Thursday morning. "When they resigned, they set something in motion that's going to be a disaster for the next long period of time."

Trump also called the protestors' demands for change "crazy."

"Many of those things are like crazy," he said.

Republican Ben Carson, the only black candidate in the 2016 race, said the resignations are a sign of the "politically correct police" going too far.

"It's OK to disagree with people, but it's not OK to destroy them," Carson said Thursday on Fox News. "People are so frightened of the politically correct police that they are willing to do things that are irrational in order to appease them. I believe it's going to be necessary for those people who truly believe in our system, who believe in our Constitution, who believe in our principles and values that made America great, to be willing to stand up."

Jeb Bush told reporters Thursday after a town hall event in Grand Rapids, Michigan that he hadn't kept up with the situation because he's "been pretty busy."

"As I understand it, (former President Tim Wolfe) didn't respond to legitimate concerns of acts of racism on campus, and may have missed an opportunity to try and heal the wounds and give people the sense that the university had no tolerance for that," Bush said. "I don't know, I haven't followed it that carefully so I can't say if his resignation was appropriate or not."

Chris Christie said Thursday that under President Barack Obama, America's racial divide has worsened.

"I don't think anyone can look objectively at where we sit as a country now and say that we're better off than we were seven years ago on the issue of race in America with Barack Obama as president," Christie told CNN's Jake Tapper on "The Lead." "In fact, I think he's made it worse."

Marco Rubio said Thursday that he's been so busy he hasn't been following the controversy. But he did raise broader concerns that free speech was being attacked at colleges.

"I am concerned about a broader issue and that is -- ah, maybe this is not related to Missouri -- freedom of speech on campus seems to be under assault in some of the finest institutions in this country," Rubio said after a campaign event with the South Carolina Chamber of Commerce.

Kentucky Sen. Rand Paul, who is also seeking the GOP presidential nomination, said Tuesday "there's a certain amount of anger out there" in response to a question about the clash between protesters and members of the media.

"I think freedom of speech is very, very important. Does freedom of speech mean there will be boorish people who say things you don't want to associate with? Yes," he said. "But really in a free society, there's got to be a place for people to make their argument."

But Democratic presidential candidates took sides with the students protesting racism at the campus.

"I'm listening to the #BlackOnCampus conversation. It's time to address structural racism on college campuses," Vermont Sen. Bernie Sanders tweeted.

I'm listening to the #BlackOnCampus conversation. It's time to address structural racism on college campuses. — Bernie Sanders (@BernieSanders) November 12, 2015

Hillary Clinton retweeted her staffer, Marlon Marshall, who wrote, "Racism has no place anywhere, let alone an institution of learning. Standing w/ the students at Mizzou in my home state calling for change."