"It was the same system that put Abraham Lincoln into office," Priebus told CNN's Wolf Blitzer, dismissing Trump's complaints against the primary process today.
That 1860 convention gave the United States one of its greatest presidents, sure. But Lincoln got the nomination through tricks and promises that might land a candidate in jail today.
"Had Lincoln's convention manager and future Supreme Court appointee David Davis been active today, he might have found his way to the court as a defendant instead of a justice," Perkins Coie attorneys Brian Svoboda and David Lazarus wrote in an analysis for the firm.
RNC spokeswoman Lindsay Walters said Priebus was making the point that the Republican Party has always played a part in selecting its nominee: "The process has been in place for a century and a half."
It just so happens that the 1860 convention fight was the subject of an episode of the CNN series, "Race for the the White House
," which detailed the gritty, backroom fight that Lincoln quietly led from Springfield, Illinois.
That twirl through the history books shows that the riots Trump has hinted
would be a near given if the current contest unfolds in the same way as it did in 1860.
Lincoln walked into the crowded Chicago convention that year as the underdog. His team of delegate wranglers needed 233 total delegates to snatch victory from then-front-runner William H. Seward -- but had only 22 in their pockets two days out from the first ballot. It would be like Ohio Gov. John Kasich working his way to the 1,237 delegates needed to clinch in 2016 from just the 145 he's won so far.
"Going from last to first meant working the ultimate insider game," said Allen C. Guelzo, author of "Abraham Lincoln: Redeemer President" on the future president's top lieutenants.
"They went to work like beavers on a damn. They worked their way into every nook, cranny and smoke-filled room they could," Guelzo said.
Former House speaker and history buff Newt Gingrich described Lincoln's team as being "quite prepared to suggest that Lincoln will remember you."
The episode documents how Lincoln's team of delegate hunters packed the convention hall by giving fake delegates counterfeit tickets.
"Sorry, but even our greatest president, our most honest president, was not above a little dirty politics," said Paul Begala, a Democratic strategist and CNN commentator.
In his 1997 book "Reelecting Lincoln," historian Richard Waugh wrote that Pennsylvania Sen. Simon Cameron was effectively guaranteed a cabinet appointment in exchange for swinging his support to Lincoln.
"For helping nominate Lincoln in Chicago in 1860, Lincoln's floor managers had promised him a cabinet seat," Waugh wrote. "Lincoln had honored the promise and appointed him secretary of war."
Back then, it was a different New Yorker who entered the convention as the odds-on favorite. Seward headed to Chicago with a lead, owing mainly to New York's sizable delegation, but watched his support dissolve over the course of three ballots.
"Make no mistake, Abraham Lincoln was chief political strategist. He relied on his aides sometimes to do the dirty work, to be ruthless, to cut deals, but he was the lead dog," said David Plouffe, former chief strategist for President Barack Obama. (Obama himself emulated Lincoln, later pulling some of his "rivals" into his administration in the same way Lincoln did after winning the presidency.)
In Republican circles, Lincoln's masterful play is still studied by operatives looking to win contested convention fights.
"He devised what was known as the 'Lincoln Four Step' for ensuring victory in an election by systematically identifying and securing supporters in an election, something that set in motion the modern precinct and grassroots-driven campaigns that are still widely seen today," wrote Michigan political operative John Yob in his recent book on contested conventions, "Chaos."