David Jackson

USA TODAY

ST. LOUIS — Following perhaps the most negative debate in U.S. political history, Hillary Clinton sought Monday to keep her leads in pre-election polls, while Donald Trump and his campaign looked to stop Republican defections from their ranks, an effort that got off to a rocky start.

House Speaker Paul Ryan, R-Wis., told a group of congressional colleagues on a conference call Monday that while he would not rescind his endorsement of Trump, he would no longer defend or campaign with him either — and that House Republicans should do what they need to in order to protect their seats and the House GOP majority in the Nov. 8 elections.

"The speaker is going to spend the next month focused entirely on protecting our congressional majorities," said Ryan spokesperson AshLee Strong.

Speaker Ryan says he won't defend Trump

Trump reacted somewhat angrily, tweeting that "Paul Ryan should spend more time on balancing the budget, jobs and illegal immigration and not waste his time on fighting Republican nominee."

Meanwhile, Republican National Committee Chairman Reince Preibus assured committee members in a call Monday afternoon that the party continued to back Trump, CNN and Politico reported.

During Sunday's debate at Washington University in St. Louis, Trump expressed regret for lewd comments he has made about women and tried to counter-attack by making allegations against his rival and her husband, former president Bill Clinton — and even suggested Hillary Clinton should be in jail and has "hate in her heart."

Trump echoed his attacks on both Clintons during a rally Monday in Ambridge, Pa., telling supporters that "we had a lot of fun" during the debate, and "I would say that Hillary is highly overrated ... She lied so much last night."

During a competing rally Monday, Clinton claimed a debate victory and said her campaign is starting to attract more independent and Republican support. "Donald Trump spent his time attacking when he should have been apologizing," the Democratic nominee said.

Things got ugly — and then uglier: Top takeaways from Clinton-Trump II

Trump entered the debate under heavy pressure over the release of a 2005 recording in which he is heard bragging about grabbing, groping, and suddenly kissing women, saying they are receptive because he is a celebrity. Dozens of Republicans called on their nominee to exit the presidential race, fearing more revelations are on the way.

A NBC News/Wall Street Journal poll — taken after the tape revelations but before the debate — gave Clinton a double-digit lead over Trump.

Following Trump tape release, Clinton surges in new poll

During the debate, the GOP nominee apologized for the video comments while dismissing them as nothing more than "locker room talk." He sought to change the narrative by extending debate invitations to women who have made sexual allegations against Bill Clinton and claimed that Hillary Clinton tried to silence them.

"Bill Clinton was abusive to women," Trump said during the debate, a claim he reiterated during his rally in Pennsylvania Monday. "Hillary Clinton attacked those same women and attacked them viciously."

Fact check: Trump's and Clinton's false and misleading claims in second debate

The New York businessman also said that, if elected, he would appoint a special prosecutor to investigate Clinton over her private emails and Clinton Foundation fundraising.

Clinton aides described Trump's aggression as a sign of implosion.

"Trump is desperate," said Clinton campaign chairman John Podesta. "He’s trying to take this race to a place in the gutter, and we’re not going there."

Clinton spokesman Brian Fallon tweeted: "So if Trump wins, he will put his opponent in jail ... If he loses the system is rigged ... Either way, he is a threat to democracy."

On Monday, President Obama weighed in on Trump's aggressive strategy, quoting his wife in a tweet: "Just like Michelle says, when they go low, we go high. @HillaryClinton went high and showed why she'll be a POTUS for all Americans."

Analysis: She called him a misogynist. He said she should go to jail.

Several Republicans said Trump did well enough in the debate to stop Republicans from calling on him to step aside — barring further revelations — but the Ryan announcement dampened his momentum.

"Trump's debate performance was strong enough to keep him viable, but Paul Ryan's decision trumps Trump," Republican pollster Frank Luntz said, adding that the GOP nominee will need an overwhelming performance in next week's third and final debate in Las Vegas to have a chance on Election Day.

"Only a home run on October 19 could propel him on November 8," he said.

GOP consultant Bruce Haynes, founding partner of Washington-based Purple Strategies, said the fundamentals of the race seem unchanged despite Trump's debate success, and he remains "an incredibly flawed candidate that very few Republicans want to stand with."

2016 Poll Tracker - USA TODAY

Sarah Isgur Flores, a Republican strategist, said Trump "may have stopped the bleeding," but still faces a narrow path to victory.

"Ryan is acknowledging what we all know," she said. "The race for the White House is over. Now it's just a question of how much collateral damage Trump can do to the (Republican) Party and our candidates."

Trump Support