"By the way, we may be given a gift from the Lord in the presidential race," Biden said in a reference to the GOP field.
"I don't know who to root for more," he said, before referencing GOP frontrunner Donald Trump. "What's the guy's name? He's having a fundraiser for veterans."
The business mogul leads the GOP field heading into the Iowa caucuses next week, and is holding a fundraiser for veterans Thursday night in Des Moines, Iowa, instead of participating in the Republican debate organized by Fox News.
Trump said he would not take part in the debate Wednesday after publicly sparring with Fox News over his feud with debate moderator and anchor Megyn Kelly.
(House Minority Leader Nancy Pelosi, D-California, who Trump said he has a "good relationship" with in an MSNBC interview earlier this week, said she expects to work with a Democratic president next year.)
Biden, in an energetic, 20-minute speech to House Democrats, urged them to contrast their record and priorities with the conservative Ryan budget passed by House Republicans in 2014, before the Wisconsin Republican became House speaker, singling out education funds cuts in the budget.
"We don't do it nearly enough," he said of making the contrast. "We never talk about what they're really for."
The vice president, who decided not to run for president last summer after grappling with the death of his son, Beau Biden, said House Democrats could "take back the House when nobody expects it" this year, an outcome most Democrats see as out of reach this cycle.