This year’s presidential primary has brought out of the shadows some of the most divisive and hateful language we’ve seen in a presidential campaign since George Wallace ran to preserve the segregated South.

Its chief perpetrator is, of course, Donald Trump, who has exceeded all previous boundaries for fanning fears and prejudices while insulting large swaths of Americans by the deft repetition of middle school taunts.

Now that Trump has the Republican nomination in sight, he has pronounced himself “the great unifier” who will bring the Republican Party together, stronger than ever. A growing number of lifelong Republicans are not amused.

Trump has done something that no public figure has achieved since World War II. He has united Republicans and Democrats, liberals and conservatives. Together, they are creating an emerging national movement to block him. The attacks on Trump from Hillary Clinton, Bernie Sanders, Ted Cruz, Marco Rubio and the political action committees from both parties are already using much of the same language.

Prominent Republican elected officials and elder statesmen are now saying they will not vote for Trump if he is the nominee, and that chorus is growing every day. Nothing like that has happened, on this scale and in public, since the Civil War.

Those Republicans who are standing up and speaking out against Trump deserve our thanks and respect because they are doing what all of us should do in times like this, which is to put our country ahead of our party.

Stopping Trump from gaining the nomination isn’t impossible if a solitary Trump opponent can emerge quickly enough. Even after Super Tuesday, Trump is still averaging only 34 percent of the votes among Republicans. But stopping him can’t be done without causing deep resentment among his supporters – and divisions within the party.

Some of those divisions would be papered over in this summer’s convention, but not many. And as Democrats learned in 1972, when they were deeply split, presidential elections that are often decided by a few percentage points are seldom won by a divided party.

Trump’s success is not as complicated as some suggest. His promise to get things done in Washington by knocking heads and cutting deals suggests that the constitution’s limits on presidential power are mere impediments that can be overwhelmed by a strong will. Generations of past presidents learned otherwise.

Trump’s instincts toward a dictatorial form of governing – which is exactly what growing numbers of Americans are now, in effect, calling for – can only produce two outcomes. One is even greater frustration with gridlocked government when Trump and reality collide, and he fails spectacularly. The other is a constitutional crisis that will make Watergate look like child’s play.

Trump’s campaign has taken up many of the issues that are roiling just below the surface of America, within the middle class and especially among Republicans. They start with a falling standard of living and sinking hopes for almost everyone who isn’t in the top strata of American society.

Added to that frustration is a boiling stew of distrust of government, declining significance in the world, new power for women, growing diversity and the loss of moral certitude in matters like marriage, sexual orientation and what constitutes appropriate appearance and language.

Most societies can withstand change – some better than others – but when rapid economic, technical and social changes converge at the same moment, it creates the conditions for a forceful backlash, and a pullback toward a lost and simpler time. And those are perfect conditions for the rise of demagogues and dictators.

The Trump phenomenon is a product of what Republicans have been sowing since Nixon’s “Southern strategy” of the late ’60s. Over time and incrementally, the national party has gradually abandoned its legacy as the inclusive party of Lincoln to become the new “Dixiecan” party, centered in the South and remote West.

The transition is now so complete that on Election Day in November, in a presidential year, a map shows that the “red” states almost completely mirror the Confederate states of 1862, along with some of the then-contested Western regions.

Republicans adopted much of the Confederacy’s “states’ rights” language and anti-Washington anger. And along with it – and despite the party’s protestations – became the tacitly white party of America.

With growing boldness, national Republicans have relentlessly stoked the ancient and smoldering divisions that always exist between “us” and “them,” through focusing on issues like crime, immigration, racial preferences, welfare and taxes.

Now the fires are raging all around them, and the party has only itself to blame for the emergence of forces that it set in motion but that it cannot now control.

Alan Caron is the owner of The Caron Group and the author of “Maine’s Next Economy” (envisionmaine.org) and “Reinventing Maine Government.” He can be contacted at:

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