Six protesters stood across the street from Burnett Park before the rally, holding signs stating: "Socialism is oppression" and "Keep TX great."
"We heard Bernie was coming to town so we thought we would come out and welcome him and tell him socialism is not welcome here," said Derrick Wilson, a member of TCU College Republicans.
Anthony Georgiev showed up because he said he disagrees with Sanders' views on gun rights and taxation.
"His values don't match with Texas values," said Georgiev, also a member of TCU's Republican group. "He simply doesn't belong in Texas."
For more than half an hour Thursday, Sanders touched on some of his traditional issues, proposals to provide Medicare for all, raise the minimum wage, improve crumbling infrastructure, make public college tuition free for all and reform the criminal justice system.
To pay for all that, he said he would rescind some Trump tax breaks and tell the top 1% and corporations to "start paying your fair share of taxes."
Sanders also defended his recent comments that Americans should be able to vote, even if they are locked up behind bars.
"I think the right to vote is what being an American citizen is all about," Sanders told the crowd. "If you commit a terrible crime, you are going to pay the price. But that doesn't mean your right to participate in democracy is taken away from you.
"Once you take away someone's right to vote, you are going down a slippery slope."
Said Wilson, one of the protesters: "That's the dumbest thing I've ever heard of in my life."