Donald J. Trump refused to say on Wednesday night that he would accept the results of the presidential election, rejecting American political norms and growing pressure from his own party by claiming that the political process is extensively rigged against him.
Mr. Trump said he would decide only on Nov. 8 whether to respect the election returns. He accused the Federal Bureau of Investigation and the media of conspiring in Mrs. Clinton’s favor, and brushed off a reminder from Chris Wallace, the debate moderator, that the peaceful transfer of power is “one of the prides of this country.”
Hillary Clinton called Mr. Trump’s answer “horrifying,” and accused him of “talking down our democracy” out of frustration with his flagging campaign.
The exchange was the closest thing to a climactic moment in which Mrs. Clinton aggressively branded Mr. Trump as a dangerous candidate, calling him a “puppet” of Vladimir V. Putin of Russia and urging voters not to entrust him with nuclear weapons.