Louis-Dreyfus offers humor, and Trump mockery, at the Democratic convention

After three nights of solemn political rhetoric at the U.S. Democratic National Convention, comedian Julia Louis-Dreyfus injected a heavy dose of humor and mockery on Thursday, all of it aimed at Republican President Donald Trump.

Louis-Dreyfus, best known as the fictional vice president on the HBO comedy "Veep," moderated the final night, firing off a string of one-liners and lightening the earnest tone of the convention to nominate Democrat Joe Biden for the White House.

When the actress described herself as a union member, climate activist and patriotic Democrat, she added, "or as Donald Trump will call me in a tweet tomorrow, a washed-up, horse-faced, no-talent, has-been with low ratings," she said.

"Well, with all due respect, sir, it takes one to know one."

After a video addressing Biden's faith, she made reference to Trump's famous walk across Washington's Lafayette Square in June for a photo-op in front of a church, aided by officers forcefully clearing the way for him through protesters.

"Just remember, Joe Biden goes to church so regularly that he doesn't even need tear gas and a bunch of federalized troops to help him get there," she said.

She added a twist to one of Trump's most famous lines from his inaugural address.

"When Donald Trump spoke at his inauguration about 'American carnage,' I assumed that was something he was against, not a campaign promise," Louis-Dreyfus said.

She met Biden, the former vice president under Barack Obama, when she starred on "Veep," she said. She was later featured in a cover story in the little-read onboard magazine of Amtrak - the train service Biden used for years to commute between Washington D.C. and his home in Delaware.

"The day it came out, my phone rang, and it was the vice president telling me he loved the cover and the whole article," Louis-Dreyfus said. "Joe Biden not only knows how to read, but also he reads everything."