President Trump extemporaneously speaks about Abraham Lincoln as if he were his rival. He has boasted that his poll numbers are greater than Lincoln’s, though there were no opinion polls in the 19th century. He has invidiously compared Lincoln with one man he always casts as heroic and whose monuments he defends as sacrosanct: “a great general,” Robert E. Lee.

And yet, to ward off criticisms of Trump’s bursts of racist rhetoric, Republican leaders reflexively play the Lincoln card. “We are the party of Lincoln,” proclaimed House Minority Leader Kevin McCarthy (R-Calif.) to shield Trump with the icon of the Great Emancipator.

But the party of Trump is the antithesis of the party of Lincoln, the culmination of a long realignment. Beginning in the 1960s, the party embraced a Southern strategy, forsaking the remnants of its Lincolnesque heritage in exchange for the principles of states’ rights and resistance to civil rights for African Americans previously associated with the neo-Confederate Dixiecrat wing of the Democratic Party. As a result, the Republican Party changed its identity and abandoned its original principles, becoming strikingly similar to the very opponents that roused Lincoln to resist in the beginning.

Lincoln created the Republican Party out of the fragments of disintegrating parties amid the political chaos of the 1850s. He had to overcome a powerful tide of anti-immigrant nativism advanced by the Know Nothing Party, which he loathed. He faced a reactionary Supreme Court, which in Dred Scott v. Sandford declared that blacks were an “inferior class” who had “no rights the white man is bound to respect,” a decision intended to smash the new Republican Party. He had to confront the most cunning demagogue of his time, Stephen A. Douglas, who hurled every racist trope against him. And he confronted a dysfunctional president, James Buchanan, whose governing incompetence let the country careen to catastrophe.

It took Lincoln time to sort out his party allegiances. He had been a stalwart member of the Whig Party since he had entered politics in the 1830s. When he emerged in 1854 to denounce the Kansas-Nebraska Act that opened the territory gained from the Mexican War to slavery, he was approached by a squad of radical abolitionists who called themselves “the Republican Party.” It was not a party, but a diffuse movement. The abolitionists saw in Lincoln the skilled and experienced politician to carry the cause effectively. He declined their invitation, considering them marginal.

With the Whigs shattered north and south, Lincoln pondered his direction. “I am a Whig; but others say there are no Whigs, and that I am an abolitionist,” he wrote an old friend in 1855. “I am not a Know-Nothing. That is certain. How could I be?” The Know Nothings, also known as the American Party, were an anti-immigrant third party that attracted many old Whigs. “How can anyone who abhors the oppression of Negroes, be in favor of degrading classes of white people?” Lincoln wrote. “Our progress in degeneracy appears to me to be pretty rapid. As a nation, we began by declaring that ‘all men are created equal.’ We now practically read it ‘all men are created equal, except Negroes.’ When the Know-Nothings get control, it will read ‘all men are created equal, except Negroes, and foreigners, and Catholics.’ When it comes to this I should prefer emigrating to some country where they make no pretense of loving liberty — to Russia, for instance, where despotism can be taken pure, and without the base alloy of hypocrisy.”

Lincoln advised abolitionists that a new party wouldn’t be sustainable until the Know Nothings cracked up and a critical mass of old Whigs gave up the anti-immigrant mania for the antislavery cause.

By 1856, the Republican Party was being organized state by state and a national convention was planned. At last, Lincoln agreed to join an organizing committee of antislavery editors to establish a new party in Illinois. At the meeting he was instrumental in passing an anti-nativist resolution. He ignored the advice of old conservative friends not to join the Republicans and worked to recruit a coalition of Whigs, Democrats, Free Soilers, abolitionists and even some former Know Nothings for the founding convention of the Illinois state party. He kept the disparate factions together on a single platform plank of opposition to the extension of slavery. Lincoln avoided using the name “Republican,” which still was thought to be dangerously radical, and called the Illinois party the “People’s Party.” Democrats tarred it with the racist label of the “Black Republican Party.”

But by 1858, Lincoln openly embraced the name of “Republican,” declaring he would put slavery “in the course of ultimate extinction.” Immigrants, he said, were “our equals in all things,” “blood of the blood, and flesh of the flesh,” because all were connected by belief in the “electric cord” of the Declaration of Independence, “the father of all moral principle.”

Then he campaigned against Sen. Stephen A. Douglas, a treacherous master of illogic, falsehood and racist invective. “Douglas will tell a lie to ten thousand people one day, even though he knows he may have to deny it to five thousand the next,” Lincoln observed. Douglas charged that Lincoln favored sexual “amalgamation” with an “inferior” race as well as “Negro equality.” The Declaration of Independence, he stated, “was made by white men for the benefit of white men.”

In their debates Lincoln sought to claim the Declaration’s author, founder of the Democratic Party, Thomas Jefferson, as a kindred spirit of the new party. Acknowledging Jefferson was a slave owner, Lincoln insisted that Jefferson’s Declaration had meant exactly what it said when it stated as a self-evident truth “that all men are created equal.” Lincoln’s expropriation of Jefferson redefined the Republican Party as its proper heir in the antislavery cause that brought together former Democrats and Whigs.

Lincoln lost that election but continued to shape the Republican Party, doubling down on the message that Democrats had betrayed Jefferson and claiming his legacy for Republicans. “I remember,” he wrote, “once being much amused at seeing two partially intoxicated men engage in a fight with their greatcoats on, which fight, after a long, and rather harmless contest, ended in each having fought himself out of his own coat, and into that of the other.” The principles of Jefferson were “now denied, and evaded” by his own party. “They would delight a convocation of crowned heads, plotting against the people. They are the vanguard — the miners, and sappers — of returning despotism. We must repulse them, or they will subjugate us,” Lincoln wrote in 1859.

Under Lincoln, the Republican Party stood for equal rights and opportunity, political democracy and using the force of the federal government to constrict and ultimately destroy the threat posed by the greatest concentrated wealth and power in the country — the Slave Power. And while the Republican Party’s origin story is one of change and compromise over time, Lincoln might be astonished to see the extent of its transformation today.

Trump’s party has embraced the ideas Lincoln opposed and fought itself into the coats of the Know Nothings and the Dixiecrats. Lincoln might also rub his eyes in disbelief to discover that sitting in his chair is the likes of Trump, the head of this redefined Republican Party, truly the rival to his principles.