Politicians are often accused of being big roadblocks to progress. And for many college students over the weekend, it was a politician who was standing in the way of them getting their diploma. Here are some themes from politicians’ commencement addresses.

Obama and Warren talk Trump

Despite being from the same party, President Barack Obama and Massachusetts Sen. Elizabeth Warren have feuded over everything from trade to appointments to the Treasury Department. But neither of them could resist taking swipes at presumptive Republican presidential nominee Donald Trump.   

In his address at Rutgers University on Sunday, Obama did not explicitly name Trump but said: “Facts, evidence, reason, logic, an understanding of science” are good things that are to be desired in elected officials.   

“So, Class of 2016, let me be as clear as I can be: In politics and in life, ignorance is not a virtue,” he said. “It’s not cool to not know what you’re talking about. That’s not keeping it real, or telling it like it is. That’s not challenging political correctness.  That’s just not knowing what you’re talking about.”  

Conversely, Warren, who recently got into a Twitter spat with Trump, was more explicit in her criticism at Bridgewater State University, south of Boston.  

“I think that Donald Trump is a truly dangerous man and there is some risk that he could be president of the United States,” she told reporters after the graduation ceremony.  

“Heck, on my day of graduation, I never imagined I would visit foreign countries. I never imagined I would be a commencement speaker. I never imagined I would get into a Twitter war with Donald Trump,” she said in her commencement address.   

Warren also gave graduates the advice to know who they are and quoted Taylor Swift’s hit song “Shake it Off.”  

“As one of the great philosophers of our time has said, ‘Haters going to hate, hate, hate, hate, hate,'” Warren said.

Boehner and Biden reunite at Notre Dame

Vice President Joseph R. Biden Jr. and former House Speaker John A. Boehner were used to letting the president speak while they sat behind him during State of the Union addresses. But on Sunday, Biden and Boehner were honored by the University of Notre Dame with the Laetare Medal, the oldest honor conferred to American Catholics.  

The university’s president highlighted their commitment to compromise and working together despite being from opposite parties and both used their addresses to highlight that and their mutual faith.  

“As speaker, I always drew a distinction between ‘compromise’ and ‘common ground,’ because I truly do believe they are different things,” Boehner said. “You can find common ground with the other side without compromising on your core beliefs. Ladies and gentlemen, Vice President Joe Biden is one of those people.”  

Biden had similar comments for the former speaker.  

“We used to treat each other with respect, hang out with each other,” he said. “John and I aren’t old school, we’re the American school.”

Clarence Thomas talks PC

Associate Supreme Court Justice Clarence Thomas used his address at Hillsdale College in Michigan to stress civic duty.  

“In addressing your own obligations and responsibilities in the right way, you actually help to ensure our liberties and our form of government,” he told graduates.  

Thomas, a Catholic, talked about the importance of standing up for one’s beliefs.  

“Do not hide your faith and your beliefs under a bushel basket, especially in this world that seems to have gone mad with political correctness,” he said.  

Contact Garcia at EricGarcia@cqrollcall.com and follow him on Twitter @EricMGarcia