"When he knows his temperament is not going over very well, he says, 'I have the temperament for the job.' When he knows that his stamina, is lagging, he says, 'I have the stamina for the job,' " Pelosi told CNN's Jake Tapper on "State of the Union."
"When he knows that he has exposure in terms of women, he projects onto Bill Clinton. When he knows that -- I don't know what this drug thing is, but I'm very suspicious that he's saying she should take a drug test; what's he talking about there?" she said. "And when he says she's engaged in an international conspiracy, whatever he's describing it as, his own people describe his advisers admitting to having back-channel conversations with the Russians."
"So I think that every time he says something, you have to look to his vulnerability on those scores," she said.
Pelosi, a California Democrat, also defended Clinton as she's under fire for saying in a speech revealed by WikiLeaks' hack of an aide's emails that environmentalists should "get a life" rather than saying the United States should no longer use fossil fuels.
"The point is this: The Republicans have been in total denial about the climate crisis that we are facing," she said, arguing that Clinton is better than GOP options.
Pelosi was also bullish on Democrats' chances to retake control of the House as Trump's poll numbers drop.
"If the election were today, we'd have a good chance to do so," she said, adding that the ultimate outcome largely "depends on how big Hillary Clinton's margin is."
"The concern I have is big, dark money coming in -- fossil fuel money, Wall Street Money, special interest money, dark, coming in in a big way," she said.
Pelosi added that House control "is definitely within reach."
Democrats would have to win gain about 30 seats to retake the House majority, something few pundits see as likely.