File: Sen. Rand Paul of Kentucky responds to questions as he meets with students from Republican groups on the campus of the University of Colorado. (AP Photo/David Zalubowski)

MILWAUKEE -- After a roundtable at a Christian school here, flanked by school choice activists and beneficiaries, the Washington Post asked Sen. Rand Paul (R-Ky.) about the protests that had broken out this week at Yale and the University of Missouri. In the first case, students were filmed hectoring a residence hall master whose wife had chided them for being over-sensitive about Halloween costumes. In the second, protests against a college president's handling of racist incidents led to that president's resignation -- then to reporters being blocked from a "safe space" for protesters, set up on the public campus.

[The Fix: University of Missouri President Tim Wolfe’s very telling resignation speech]

"It is somewhat ironic to many of us," Paul said. "When we went to college, it was the place where you expressed yourself. You could say anything. You heard from people that came from a different point of view, and ideas clashed. People formed their own ideas. Freedom of speech is very important. Does freedom of speech mean that there will be boorish people who say things that people don't want to associate with? Yes, and people shun them."

Paul said he could appreciate why students would feel demeaned or threatened by structural racism -- "there's a certain amount of anger out there" -- but the crux of his message was that respect for speech had been lost on campus.

He was not the only conservative saying that. The argument between conservative politicians and liberal academics is at least as old as the modern conservative movement -- something one can date from the publication of William F. Buckley's "God and Man at Yale." Flare-ups of student activism or political correctness on campus have frequently become grist for Republican campaigns, from then-governor Ronald Reagan's crackdowns at the University of California to then-governor Bill Owens's successful ouster of University of Colorado professor Ward Churchill.

In Wisconsin, where Gov. Scott Walker (R) enjoys thumping Republican legislative majorities, colleges have proven especially easy to attack. Earlier this year, Walker was briefly embarrassed after an education funding proposal removed "the Wisconsin idea," to "extend knowledge and its application beyond the boundaries of its campus," from public universities' mandate. Even after that language was removed, Walker signed off on reforms that cut $250 million from the state university system and made it easier for colleges to fire tenured professors -- downgrading the cause from a financial emergency to a simple program change.

[Scott Walker is a diminished figure — except in the state he governs]

Walker, like many Republicans, cast this as a way to make colleges more responsive to needs, and to turn out more employable people. When he speaks on college campuses, or when a parent lobs him a question about tuition costs, Gov. Chris Christie (R-N.J.) typically uncorks a tirade about the opaque and bloated costs of the modern college. It starts as a riff on how no restaurant could bill for "food" the way a college bills for "tuition," with so little detail about the expenditures, and it continues with Christie asking why every college gym seems to have a rock-climbing wall.

"This is New Hampshire -- you have rocks right out there!" Christie said at a summer event at the University of New Hampshire. "What the hell do you need a rock climbing wall for? Tell the kids at UNH, ‘Go outside and climb those rocks.'"

Sen. Marco Rubio (R-Fla.), who brought his rising campaign to conservative Waukesha County Monday, told an audience with plenty of young faces that liberal arts simply were not as good an investment for them as vocational schools. He suggested that elites had "told young Americans that trade schools and vocational training were for kids that weren't smart enough for college."

That argument was at odds with President Obama's own education policies, but perfectly in sync with conservative arguments against the wastrel liberal arts. In his 2012 primary campaign, former Pennsylvania snator Rick Santorum made a passionate version of the same argument, calling the president a "snob" for allegedly viewing vocational school as less valuable than four-year colleges. Rubio, who is far ahead of Santorum in polls, created a dichotomy between a money-burning philosophy degree and a money-printing blue collar job.

"The market's been tight for philosophers for around 2,000 years," Rubio said. "A welder makes a lot more than a philosopher. I want to be the vocational education president, someone who makes it easier to get into those fields. Someone who opens up Pell Grants, and says if a 16-year-old wants to be an auto mechanic, or an aircraft mechanic, or a machinist, let them go to high school in the morning and use the Pell Grant to go to trade school in the afternoon, so that when they're 18 years old and they graduate they have a job making $50,000 a year."

Just as labor unions are resilient sources of Democratic campaign funds and voter turnout, universities are seen as beachheads of the left, where radicals defeated in the 1960s were able to built a counterculture that influenced everyone who came through it. If four-year schools became a punchline, cutting funding, or redirecting grant money, became much more simple. In Waukesha County, Rubio proved why.

"That doesn't mean we're not going to have four-year schools," cautioned Rubio. "Of course we are. We need college football." When the laughter subsided, Rubio provided a caveat: "That's only a partial joke, by the way."