Republican presidential nominee Donald Trump said Tuesday that a lack of support from House Speaker Paul Ryan has made it "hard to do well," in an apparent acknowledgment of the political damage of increasing GOP infighting."Despite winning the second debate in a landslide (every poll), it is hard to do well when Paul Ryan and others give zero support!" Trump said on Twitter.

Trump's remark came a day after Ryan effectively disavowed him — without formally pulling his endorsement — and a poll showed Trump trailing Democratic nominee Hillary Clinton by double digits ahead of November's election.A 2005 video that surfaced Friday of Trump bragging about groping women prompted a wave of Republican lawmakers to withdraw their support in a last-ditch effort to save their control of Congress. Others, including Republican National Committee Chairman Reince Priebus and vice presidential nominee Mike Pence, are standing by Trump.

Trump tweeted Monday that Ryan "should spend more time on balancing the budget, jobs and illegal immigration and not waste his time on fighting Republican nominee," but his remark Tuesday went further in alluding to his worsening chances.

Trump has heralded unscientific online reader polls on news websites that showed him winning Sunday's second presidential debate. In fact, three more methodologically sound surveys by professional pollsters showed Clinton was seen as the better debater by margins ranging from 5 to 14 percentage points.

Nationally, Clinton has about a 5-point edge on Trump in a race that includes third-party candidates, according to the RealClearPolitics poll average. The forecaster FiveThirtyEight on Monday gave Clinton an 82.9 percent change of winning in its polls-only model, approaching her high of 89.2 percent in mid-August. FiveThirtyEight gave Democrats a 52.6 percent change of winning back the U.S. Senate.