President Barack Obama continued a Democratic full-court press on down-ballot Republicans, campaigning and cutting ads in key Senate and House races.

Holding a solid lead over Republican Donald Trump, Hillary Clinton has also turned her attention to those races, too. She will likely give some aid to North Carolina Senate challenger Deborah Ross when she campaigns in Winston-Salem with Michelle Obama on Thursday.

Her campaign and outside groups who support Democrats are shifting resources from the presidential race to House and Senate candidates, too.

Clinton is also expected to campaign with New Hampshire Gov. Maggie Hassan, who is running for senate against Republican Sen. Kelly Ayotte.

Obama on Sunday took on one of his fiercest congressional critics in California at a fundraiser for Democrats that included Democrat Doug Applegate, who’s mounting a stronger-than-expected challenge to Rep. Darrell Issa.

At a fundraiser, Obama reminded the crowd that Issa has refused to distance himself from Trump and gave him part of the blame for Trump’s rise.

“This guy has spent all his time simply trying to obstruct, to feed the same sentiments that resulted in Donald Trump becoming their nominee,” Obama said.

Issa pushed back against Obama, saying he has worked with the White House when possible along with criticizing it.

“I’m disappointed but not surprised that the president, in a political speech, continues to deny accountability for the serious scandals that happened under his watch where Americans died overseas and veterans have died here at home,” Issa said in a statement.

Earlier Sunday in Nevada, Obama also used Trump against Rep. Joe Heck, who is running against Democrat Catherine Cortez Masto for retiring Senate Minority Leader Harry Reid‘s seat.

“There’s one other difference between the candidates: Catherine never supported Donald Trump,” Obama told a crowd in North Las Vegas. “She never said she had ‘high hopes’ he would become president. Never said she’d trust his fingers on the nuclear code.”

Calling out Heck for rescinding his endorsement of his party’s presidential candidate after a 2005 video of Trump suggesting he had sexually assaulted women emerged, Obama said, “Now that Trump’s poll numbers are cratering, suddenly he says, ‘No, I’m not supporting him,’” Obama said. “Too late. You don’t get credit for that.”

Obama also made a pitch to Nevada voters for House candidates Jacky Rosen and Ruben Kihuen.

“You’ve got an ace and you’ve got a jack. You’ve got to make sure you turn over the card by voting,” he said.

On Monday, Obama announced the endorsement of 30 Democratic House candidates and incumbents. The president has cut a series of ads for down-ballot Democrats, like former Rep. Brad Schneider in Obama’s home state of Illinois and for Bryan Caforio in California.

He also appeared in an ad for former Charlie Crist, a former Republican governor of Florida who left the GOP after being criticized for supporting Obama’s economic stimulus plan in 2009.

Obama’s visit came after Vice President Joseph R. Biden campaigned in Nevada with Cortez Masto to rally labor support. The vice president will campaign this week in Missouri for Democrat Jason Kander, who’s giving Republican Sen. Roy Blunt and unexpectedly strong challenge.

Biden also is featured in an ad for Pennsylvania Democratic senate candidate Katie McGinty, criticizing ads against her “a bunch of malarkey.”