Where did the GOP think this would lead?

Mainstream Republicans are watching these developments at the top of the ticket with a growing sense of alarm, calling Trump’s latest conspiracy theories of a rigged election irresponsible and dangerous. They also say the impact of voter fraud or errors on the outcome of elections is vastly overblown.

“How do you proclaim fraud before the incident takes place? It’s like my calling you a robber before you rob the bank,” said Al Cardenas, who was chairman of the Republican Party of Florida during the 2000 electoral recount. “In America, you call out a crime or malfeasance after it happens.”

Cardenas, having been immersed in the Florida recount for 37 days, said an average of 1.5 percent of votes cast in the nation are not recorded, due mostly to technical issues and procedural errors.

“That’s a significant number in a close election, but they are not wrongdoings,” Cardenas said. “Americans should feel that the ultimate outcome of the election is fair. That’s how we defend our democracy.”

Cardenas said he would not vote for Trump or Clinton — even if that means Clinton wins.

“Hey, the radicals had their day,’’ he said. “This is the result of it.”

Fergus Cullen, former chairman of the New Hampshire GOP, said it was an incredibly important moment in 2000 when Democrat Al Gore gave a speech saying he accepted the results of the Supreme Court decision to award the majority of electoral votes and presidential victory to George W. Bush.

“Had he not done that, or done so halfheartedly, or even suggested that he’d been robbed, or otherwise tried to delegitimize the results, it would have been a huge blow to our democratic process,” Cullen said.

Cullen expects Trump’s warnings about a rigged election to get even uglier in coming weeks, and he fears they will incite violence if Trump loses.

“That’s really scary,” Cullen said, recounting the violence at Trump rallies around the country leading up to the Republican National Convention. “In this country, we’ve always had recriminations after one side loses. But we haven’t had riots. We haven’t had mobs that act out with violence against supporters of the other side. There’s no telling what his supporters would be willing to do at the slightest encouragement from their candidate.”

While voters have certainly questioned election outcomes, it is unprecedented for the nominee of a major party to do so, historians say.

“What’s really distinct is the candidate himself putting this out front and center as a consistent theme throughout the last part of the campaign, and doing it when there’s no evidence of anything,” said Julian Zelizer, a Princeton University presidential scholar.

Some of Richard Nixon supporters in 1960 claimed that John F. Kennedy’s father bought the election for his son in Chicago. Many Democrats in 2000 felt the Supreme Court intervened on behalf of Bush. Fringe conservatives in 2008 launched the birther movement, which Trump joined with gusto in 2011, in an attempt to delegitimize Barack Obama’s presidency.

“If Clinton is elected, as it looks like she will be, they will be convinced she should not be president because the Republican nominee has confirmed their own fears, anxieties, and conspiratorial outlook,” Zelizer said. “It will make governing more difficult.”

“The Republican Party, the strategists, the consultants, they firmly believe that early voting is bad for Republican Party candidates. It’s done for one reason and one reason only ... ‘We’ve got to cut down on early voting because early voting is not good for us,."