Michael Wines with the absolute must-read in the NYT:

In asserting that the presidential election has been rigged against him and casting accusations of widespread voter fraud, Donald J. Trump has tapped deep into an increasingly prevalent theme of Republican Party politics: that Democrats try to steal elections, not win them.

It is the culmination of roughly two decades of alarms, investigations and political gamesmanship in which remarkably little voter fraud has been documented, but the conviction that it is widespread has gone from a fringe notion to an article of faith for many Republicans.

The Republican focus on voter fraud dates to the late 1990s, when the 1993 National Voter Registration Act — the “motor-voter” law — was put in place. Republicans in particular, but some election administrators as well, began to complain that registering had become too easy and ill supervised to spot ineligible voters.

The stakes for both parties in election rules and who gets to vote became glaringly clear in 2000, when a 537-vote court-challenged victory in Florida’s presidential election sent George W. Bush to the White House.

In the same election, accusations of voter fraud became a volatile issuein Missouri. Republicans claimed that Democrats in St. Louis were trying to steal that state’s Senate election after lawyers for Al Gore’s campaign won a court order keeping the city’s polls open late to accommodate voters who had been wrongly removed from the rolls.

And issues of race, often a subtext in Republican charges of fraud, were accentuated by the election of the nation’s first black president in 2008. Republicans accusations of voter fraud, as in St. Louis, have frequently been directed at minority groups in cities such as Philadelphia and Chicago. The issue now thrives in the hothouse of the internet, where corrections of fact and debunkings rarely catch up with the claims they address.

Mr. Trump’s pronouncement “did not come out of thin air,” Richard L. Hasen, an election law expert and professor at the University of California, Irvine, said in an interview. “It is, in fact, an often-repeated theme by those on the right who have been claiming, especially since 2000, that Democrats are stealing elections with voter fraud.”