Not in a million years would Republican power brokers have imagined a future like the one that's unfolding before them.

As the curtain rises on the 2016 presidential campaign, they are in crisis. The voters they incited with decades of what turned out to be empty promises of a sweeping revolution in Washington are now turning on them for failing to deliver.

Countless others who disengaged from politics long ago are returning to the fray with pitchforks and torches, rejuvenated by the prospect of sending the party a message by burning it down.

The Republican managerial class — the fixers, the spinners, the donors, the thinkers and, arguably, Fox News — has been caught in flat-footed disarray.

Across the aisle, Democrats are experiencing their own rude awakening, although in a less panic-inducing way.

The presumed inevitability of Hillary Clinton has come up against the unexpected irresistibility of Independent Senator Bernie Sanders, a self-described democratic socialist from Vermont who speaks Brooklynese and is running as a Democrat in the nomination race.

At one point, Florida Senator Marco Rubio, a son of Cuban immigrants with Tea Party support, seemed like the perfect candidate to expand the Republican base. But the bipartisan immigration bill he championed failed and only served to alienate Republicans that blamed cheap immigrant labour for driving down wages. (Andrew Harnik/Associated Press)

He's 74 years old, and his strongest support is among young people

In both parties, the insurgency has something to do with the insecurity people are feeling about an economy they believe doesn't work for ordinary people anymore.

But it is in the Republican base where you find a deep sense of personal betrayal.

Can Republicans live with Trump's baggage?

For the moment, the accumulation of simmering discontent among the Republican grassroots is at the service of Donald Trump.

In a couple of days, all eyes will turn to Iowa to see whether his sensationally durable performance in public opinion polls ("I'm leading everywhere!") translates into votes.

This pamphlet being shared among Republican supporters of Donald Trump in Maryland speaks to the disenchantment with establishment politics that is driving support for Trump. (Courtesy of Ed Hunter)

If it does, then all Republicans will have a decision to make: Can they live with a presidential candidate who calls women "bimbos," is endorsed by neo-Nazis, promises to round up and deport 11 million undocumented immigrants, has called for a temporary ban on Muslims coming to the U.S., would start a trade war with China and counsels targeting women and children in the fight against ISIS (a war crime, say some)?

Can they live with all that?

Or how about Trump's less-outrageous views that, nevertheless, fall outside Republican orthodoxy?

Leading anti-abortion groups, pointing to Trump's claim that he's "very pro-choice," have called for Republicans to vote for any other candidate but Trump.

Heading into the Iowa caucuses, opinion polls show Trump far ahead of candidates such as Jeb Bush, above, Rubio, and Ben Carson. Only Ted Cruz comes close to the former real estate magnate, but even he has only about half the support that Trump has. (Charlie Neibergall/Associated Press)

"He's not even a conservative!" say conservatives.

Last week, the National Review, which claims to be "America's most widely read and influential magazine for conservative news, commentary and opinion," devoted an entire issue to piling on Trump, calling him "a menace," "crazy," and "American Mussolini."

Trump dismissed it with a tweet that described the National Review as "a failing publication that has lost its way."

Establishment vs. grassroots

It would be surprising if the National Review were even known much less read among the millions who are backing Trump.

They're not waging a battle for conservatism. What they are doing, they believe, is finally turning the tables on the Republican Party, using it instead of being used by it.

The Iowa caucuses, which begin Monday, will be a test of Trump's grassroots support. Will his boast of 'I'm leading everywhere!' translate into votes? (Paul Sancya/Associated Press)

Such a confrontation between the Republican establishment and its grassroots was probably inevitable.

You can trace its roots back decades, or begin with the last presidential election.

In the post mortem that followed Mitt Romney's defeat in 2012, Republicans looking to the future concluded the party needed to embrace the changing face of America.

To win the White House back, they believed, meant expanding their voting base to include more Asians, African Americans and, especially, Hispanics — the fastest growing ethnic minority in the country.

An important step, some thought, would be to get behind immigration reform.

And so they did, sort of. Florida Senator Marco Rubio looked as though he had all the bases covered — rising Republican star, elected with Tea Party support, son of Cuban immigrants — to spearhead the Republican side in a bipartisan push for an immigration reform law.

Simple fixes

Rubio was the lead Republican in the group behind a Senate bill that would bring some undocumented immigrants out of the shadows and put them on a path to citizenship.

The bill passed the Democrat-controlled Senate, then died a slow death in the Republican-controlled House.

But it was a warning flare that lit up the sky above millions of Americans who were struggling in a difficult economy and blaming cheap immigrant labour for driving down wages.

The Democrats are experiencing their own insurgency in the form of Independent Senator Bernie Sanders, who is vying for the Democratic nomination and commanding strong support in opinion polls, especially among the party's younger members. (Evan Vucci/Associated Press)

They believed that for the sake of satisfying "the donor class" and winning the White House back, their party was preparing to sell them out and make more room for immigrants, whom, they thought, already had too much room.

The confrontation that will begin to play itself out in the Iowa caucuses on Monday will have historic consequences. - Keith Boag

In their moment of despair, Trump arrived saying he would round up Mexicans and send them back to where they'd come from. It would be easy, and America would be "great again," he said.

And he had simple fixes for all the other big problems in the world, too. Problems that were confounding America only because American leaders were "really stupid people," he said.

But to his critics — polls show he has more of them than he has fans — Trump sounded as though he were rallying Americans to a half-remembered golden age when, for the white, male, straight and Christian, things weren't so shabby.

Divisions won't end with Trump

The confrontation that will begin to play itself out in the Iowa caucuses on Monday will have historic consequences. And because it didn't start with Trump, it won't end with Trump.

If his campaign is derailed, his supporters will still be around, and they will still be angry. But they will be better organized than they were before they and Trump found each other.

What their next move will be is a worrisome pre-occupation for those who think the marginalization of the Republican Party nationally is a bad thing for American democracy.

The GOP establishment won't understand its time is up until it's too late, says Ed Hunter, a Maryland Tea Party member and Donald Trump supporter. (CBC)

A Maryland Tea Party and Trump supporter I keep in contact with, Ed Hunter, recently sent me a pamphlet his group is passing around.

At the top in big bright letters it says, "Donald Trump 2016" next to a stylized rearing lion. At the bottom, it says, "Because this isn't working" next to the Democratic donkey and the Republican elephant.

Hunter also gets a kick out of sharing a YouTube video of former Romanian leader Nicolas Ceausescu's final speech to a crowd outside his palace in December 1989.

Ceausescu has hardly begun to speak when he senses rising anger and insolence. He tries to buy time with an improvised promise of higher wages.

Within days, he's dead, executed by a firing squad.

"He didn't understand his game was up until the last second," says Hunter. "Same with the GOP establishment."