Donald Trump on Tuesday launched an attack on the Republican Party's top elected official for giving him "zero support," escalating his feud with the party establishment.
Paul Ryan, the speaker of the House of Representatives, and other prominent party members said earlier they could no longer defend their nominee for president.
"It is so nice that the shackles have been taken off me and I can now fight for America the way I want to," Trump said on Twitter.
"Disloyal R's are far more difficult than Crooked Hillary. They come at you from all sides. They don’t know how to win - I will teach them!" Trump added in a subsequent tweet.
Ryan told Republican lawmakers on a conference call Monday that he would no longer campaign for Trump in the wake of the release of a decade-old video in which Trump boasts about sexually assaulting women.
"Our very weak and ineffective leader, Paul Ryan, had a bad conference call where his members went wild at his disloyalty," Trump said in an earlier tweet.
"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 tweeted.
The scandal deepened the fracture within the party less than a month before the election, with dozens of Republicans announcing that they were no longer supporting Trump's presidential bid.
New Jersey Governor Chris Christie, a one-time rival of Trump's for the Republican nomination who is now a close confidant, piled on the criticism in an interview Tuesday - but stopped short of pulling his support.
"On the video itself, let's be really clear — it is completely indefensible and I won't defend and haven't defended it," he told WFAN radio.
"That kind of talk and conversation, even in private, is just unacceptable," Christie said
Democratic rival Hillary Clinton has opened up a double-digit lead over Trump, according to some national polls taken after the release of the video.
Trump has apologized for talking in the 2005 video about grabbing women "by the pussy," chalking it up to "locker room talk."
Clinton meanwhile appeared with former Vice President Al Gore in Miami, Florida. Gore lost his presidential bid in 2000 after losing in the state of Florida by only a few hundred votes.
President Barack Obama found comments made by Trump in a leaked video from 2005 "as repugnant as most Americans did," his spokesman said Tuesday.
There also has been a "clear statement by people all along the ideological spectrum that those statements constituted sexual assault," Johsh Earnest said.