For decades, the left sought to dethrone the idea of truth. Truth was not an absolute. It was a matter of power. Of perspective. Of narrative. "Truth is a thing of this world," wrote Michel Foucault. "Each society has its regime of truth, its 'general politics' of truth: that is, the types of discourse which it accepts and makes function as true."

Then Kellyanne Conway gave us "alternative facts" and Rudy Giuliani said, "Truth isn't truth" — and progressives rushed to defend the inviolability of facts and truth.

For decades, the left sought to dethrone reverence for the Constitution. "The Constitution," wrote progressive historian Howard Zinn, "serves the interests of a wealthy elite" and enables "the elite to keep control with a minimum of coercion, a maximum of law — all made palatable by the fanfare of patriotism and unity."

Then Donald Trump attacked freedom of the press and birthright citizenship, and flouted the emoluments clause, and assailed the impartiality of the judiciary. And progressives rediscovered the treasure that is our Constitutional inheritance.

For decades, the left sought to enthrone identity politics. "We believe that the most profound and potentially most radical politics come directly out of our own identity, as opposed to working to end somebody else's oppression," reads the 1977 statement of the black feminist Combahee River Collective, one of the key documents in the development of contemporary U.S. identity politics.

Then Trump turned identity politics on its head by appealing to white voters, and progressives rediscovered the beauty of our national motto, emE pluribus unum./em

The list goes on. Bad morals in a president? With Bill Clinton in office, the left was basically indifferent. With Donald Trump, it's indignant. Intense hostility to Russia? Previously a sign of paranoia; currently a prerequisite to patriotism. Accusing the CIA or FBI of conspiring against our freedom? What was once emde rigueur/em among progressives is now a slur on the good name of people who keep us safe.

Which brings me to Elizabeth Warren's commencement address last Friday at Morgan State University in Baltimore. It sounded just like ... a Trump stump speech.

To an audience of nearly 500 new graduates and their families at the historically black college, the Massachusetts senator laid out a bleak vision of America. "The rules are rigged because the rich and powerful have bought and paid for too many politicians," she said. "The rich and powerful want us pointing fingers at each other so we won't notice they are getting richer and more powerful," she said. "Two sets of rules: one for the wealthy and the well-connected. And one for everybody else," she said.

"That's how a rigged system works," she said.

It was a curious vision coming from a person whose life story, like that of tens millions of Americans who have risen far above their small beginnings, refutes her own thesis. It was curious, also, coming from someone who presumably believes that various forms of rigging emare /emrequired to un-rig past rigging. Affirmative action in college admissions and aggressive minority recruitment in corporations are also forms of "rigging."

But however one feels about various types of rigging, the echo of Trump was unmistakable. "It's being proven we have a rigged system," the president said at one of his rallies last year. "Doesn't happen so easy. But this system — gonna be a lot of changes. This is a rigged system."

Trump's claim that the system is rigged represents yet another instance of his ideological pickpocketing of progressives. From C. Wright Mills ("The Power Elite") to Noam Chomsky ("Manufacturing Consent"), the animating belief of the far left has been, as Tom Hayden put it, that we live in a "false democracy," controlled by an unaccountable, deceitful and shadowy elite. Trump has names for it: the globalists; the deep state; the fake news. Orange, it turns out, is the new red.

Of course, Warren and Trump have very different ideas as to just who the malefactors of great wealth really are. Is it Sheldon Adelson or George Soros? The Koch brothers or the Ford Foundation? Posterity will be forgiven if it loses track of which alleged conspiracy to rig the system was of the far-right and which was of the far left.

What it will remember is that here was another era in which a president and one of his leading opponents abandoned the prouder traditions of American politics in favor of paranoid ones. Compare Warren's grim message to Bill Clinton's sunny one from his first inaugural: "There is nothing wrong with America that cannot be cured by what is right with America."

At some point, it will be worth asking Warren: Rigged compared to when? A generation ago a black president would have been unthinkable. Two generations ago, a woman on the Supreme Court. And rigged compared to what? Electoral politics in Japan, which have been dominated by a single party for decades? The class system in Brazil, dominated by a single race for centuries?

For now, Democratic voters might think twice about embracing a candidate whose dark, distorting ideas about America bear such an uncomfortable resemblance to those of the president they detest. Wouldn't it be nice to have an optimist in the White House once again?