MINNEAPOLIS -- Senator Bernie Sanders made two campaign stops Tuesday in Minnesota on behalf of his former primary campaign rival Hillary Clinton.

A capacity crowd of 1,800 gave Sen. Sanders a rock star welcome, as he took the stage at Northrop Auditorium at the University of Minnesota. Dozens of students surrounded the Vermont Senator to grab selfies with him.

"Politics is not a personality contest! It’s not about who like, who you don’t like, about who you’re going to have a beer with or not," Sanders declared. "It’s about the future of our country and what happens to the middle class, and the working people of this country!"

He came to convince the same group of young voters who helped propel him to a decisive victory in the Minnesota DFL Caucuses last March to support Secretary Clinton in November.

Sanders spent several minutes on the tuition-free college proposal he initiated and Clinton later adopted, saying that educating the work force and freeing young workers from the burden of student debt can do more to transform the economy than Trump's proposals such as eliminating the estate tax on the top two percent.

"If you look at which candidate has the ideas to protect working families, the answer is clear -- the answer is Hillary Clinton."

Sanders also went after the GOP standard bearer on climate change.

"Donald Trump thinks that climate change is a hoax, originating in China. I was surprised to hear him say that. I would’ve thought he thought it came from Mexico, or a Muslim country!" Sanders remarked.

"You cannot have sane, rational public policy if you reject science, which is precisely what Trump and a number of other Republicans are doing."

He said Trump would work to reverse the strides made in racial and gender equity, pointing out Trump's role in the Birther movement.

"That movement was about trying to undermine the legitimacy of the first African American president in our history, that’s what that was about! Racist! Pure and simple!"

GOP response

The Trump Campaign, in anticipation of Sander's visit issued the following statement:

"What a surprise -- with polls showing support for Hillary in the basement with Millennial voters, her campaign sends Bernie Sanders to Minnesota to manufacture a portrait of enthusiasm for her candidacy.

"Unfortunately for Bernie, he's having to shill for his former rival the very week it was revealed Hillary talked down to these same young voters for 'living in their parents' basement' and being stuck in a 'job that doesn't pay a lot'."

Minnesota Republican Party Chair Keith Downey held a press conference before Sanders' visit, accusing Sanders of betraying his own supporters.

"Bernie Sanders was exactly right about Hillary Clinton in the primaries, and now that he has sold out his supporters and endorsed her he’s got a lot of explaining to do while he’s in Minnesota today."

The leader of the College Republicans in Minnesota, Amanda Peterson, said several people wearing Trump apparel on college campuses in the state had been harassed and intimidated, and that the U of M College Republicans office had been vandalized. She called on Sanders and Clinton to condemn such behavior.

On Tuesday night Sanders traveled to the University of Minnesota Duluth, and received a rousing welcome at the Kirby Ballroom. He was there on behalf of the Clinton campaign and to bolster the efforts of 8th District Congressman Rick Nolan, who faces a tough challenge from Republican Stewart Mills III.

Some Iron Range Democrats are leaning Trump because of frustration over China's dumping of cheap steel in the US market, which has led to the loss of jobs in that part of Minnesota.