Donald J. Trump has lashed out at fellow Republicans, calling them “disloyal” and “far more difficult” than Hillary Clinton. He has griped openly about a “rigged” political system, saying Wednesday he has “no respect” for the nonpartisan Commission on Presidential Debates and complaining about a “defective” microphone in the first debate. And on Monday, at a rally in Wilkes-Barre, Pa., he worried the election could be “stolen” from him and singled out Philadelphia, a city with a large African-American population, warning, “We have to make sure we’re protected.” Mr. Trump’s ominous claims of a “stolen election” — which he often links to black, urban neighborhoods — are not entirely new. But in recent days, he has been pressing the theme with a fresh intensity, citing everything from the potential for Election Day fraud to media bias favoring Mrs. Clinton to rigged debates.
The assertions — which coincide with Mr. Trump’s decline in the polls in the wake of a shaky first debate performance and accusations he forced himself on women — highlight concerns that he may not accept a Clinton victory, breaking from the traditional decorum of defeated presidential candidates and undermining the legitimacy of the election result.
At rallies in recent days, Mr. Trump has become a candidate seething with excuses, perhaps the clearest manifestation of his frustration with his current standing in the polls and the growing alarm within his campaign that a White House victory is slipping away.
On Monday, on a trip through Pennsylvania, Mr. Trump began the day urging the almost entirely white crowd outside Pittsburgh to show up to vote, warning about “other communities” that could hijack his victory.