By Eugene Robinson –

History will remember 2015 as the year when The Republican Party As We Knew It was destroyed by Donald Trump. An entity called the GOP will survive – but can never be the same.

Am I overstating Trump’s impact, given that not a single vote has been cast? Hardly. I’m not sure it’s possible to exaggerate how the Trump phenomenon has torn the party apart, revealing a chasm between establishment and base that is far too wide to bridge with stale Reagan-era rhetoric.

Can you picture the Trump legions meekly falling in line behind Jeb Bush or Marco Rubio? I can’t either.

Trump didn’t blow up the party on his own. He had help from a field of presidential contenders that was touted as deep and talented but proved shallow and wanting. Bush raised shock-and-awe money but turns out to lack his father’s and brother’s skill at performing on the national stage; he seems to want to be crowned, not elected. Rubio is like the teacher’s pet who speaks eloquently in class but doesn’t do his homework. Chris Christie was slow off the mark, perhaps having been stuck in traffic on the George Washington Bridge.

Who else would be acceptable to the GOP establishment? Certainly not Rand Paul. Rick Santorum, Mike Huckabee and John Kasich all had their glory days in the last century. Carly Fiorina has never held elective office. Scott Walker, Rick Perry, Bobby Jindal and Lindsey Graham have come and gone.

At year’s end, the campaign is dominated by three candidates who appeal over the heads of the establishment and straight to the unruly base: Ted Cruz, who negates the fact that he is a sitting senator by waging all-out war against the party leadership; Ben Carson, a distinguished neurosurgeon who seems increasingly out of his depth; and Trump, the undeniable front-runner.

What Trump has done is call out the establishment on years of dishonest rhetoric. Progressives often asked why so many working-class whites went against their own economic interests by supporting the GOP. The answer is that Republicans appealed to these voters on cultural grounds, subtly exploiting their resentments and fears.

The nation’s demographics are changing, with a rapidly growing Latino population—and an African-American in the White House. Globalization has hollowed out the middle class. The country is vulnerable to terrorism and there is no way to impose a Pax Americana upon today’s multipolar world.

The Republican Party promised—with nods, winks and dog-whistle toots—to change all of this and make everything the way it used to be. In practice, however, party leaders were compelled to deal with the world as it actually is. Hence, for example, the establishment view a couple of years ago in favor of comprehensive immigration reform.

Enter Trump, who has the temerity to point out that the party establishment says one thing but does another. He launched his campaign by calling the GOP’s bluff on immigration: If the 11 million people here without documents are really “illegal,” as the party loudly proclaims, then send them home. Other candidates were put in the position of having to explain why, after claiming that President Obama was somehow “soft” on immigration, their position on allowing the undocumented to stay is basically the same.

Similarly, many leading Republicans were careful not to offend the “birthers” who denied Obama’s legitimacy as president. An unabashed birther long before he was a candidate, Trump still refuses to say whether he accepts the proven fact that Obama was born in the United States.

Also, the party has long sought to capitalize on fear of terrorism by haranguing the president for not using the exact phrase “radical Islamic terrorism” (as if semantics could bring peace to Syria). So when, after the San Bernardino attack, Trump called for banning Muslims from entering the country, much of the Republican base was receptive. Other candidates had to backpedal and remind voters that George W. Bush made clear his “war on terror” was not a war against Islam.

Trump has given voice to the ugliness and anger that the party spent years encouraging and exploiting. He let the cat out of the bag, and it’s hungry.

The party might nominate Trump, in which case the establishment will have lost all control. Or party leaders might somehow find a way to defeat him, in which case they will have lost the allegiance of much of the base. In either event, the GOP we once knew is irredeemably a thing of the past.