The long-running Republican war against the right to vote has now gone national at the instigation of President-elect Donald Trump, who has promoted the lie that millions of illegal votes were cast in the presidential election.

There is not a scintilla of evidence for this claim, and Mr. Trump’s own lawyers have admitted as much, stating in a court filing opposing a recount in Michigan that “all available evidence suggests that the 2016 general election was not tainted by fraud or mistake.”

Yet one after the next, leading Republicans are spreading this slander of American democracy, smoothing the way to restrict voting rights across the country.

On Sunday, Vice President-elect Mike Pence told ABC’s George Stephanopoulos that it was Mr. Trump’s “right to express his opinion as president-elect.” When pushed to admit that the illegal-voting claim was not true, Mr. Pence shifted the burden of proof away from Mr. Trump, even though Mr. Trump has accused millions of Americans of committing a crime. “Look,” Mr. Pence said, “I don’t know that that’s a false statement, George, and neither do you.”