The House Republicans’ campaign arm launched an ad targeting Vice President Harris on Wednesday, as some Democrats call on her to replace President Biden at the top of the party’s November ticket.

“House Republicans are sharpening our knives if extreme House Democrats dump Joe Biden — or we will remind voters Kamala Harris is next in line if they don’t,” the National Republican Congressional Committee (NRCC) wrote in an announcement.

The ad features a voiceover of Harris complimenting Biden and a compilation of House Democrats — including former Speaker Nancy Pelosi (D-Calif.) and Rep. Jim Clyburn (D-S.C.) — praising the vice president.

“Is this who we want to be president?” the ad asks.

Democrats critical of Biden have increasingly looked to Harris as a potential replacement for the president, after a poor debate performance last week raised concerns over whether he can win the November election.

The vice president has backed Biden publicly, and the Biden campaign has brushed off the criticism, quickly shutting down any idea that the president would leave the race.

Rep. Lloyd Doggett (D-Texas) became the first sitting member of Congress to call on Biden to leave the race Tuesday, while also encouraging Harris to take the mantle. Other members, including close Biden ally Rep. Jim Clyburn (D-S.C.), have said they would back Harris if Biden steps down, though have not called on him to do so.

A CNN poll Tuesday showed Trump now beating Biden nationwide by 6 points, 49 percent support to 43 percent. The same poll showed Trump leading Harris by a narrower margin, 47 percent support to 45 percent.

The poll also showed that 56 percent of Democratic voters and Democratic-leaning independent voters think their party would have a better chance of winning the White House with someone other than Biden. Only 43 percent of these voters said they think Biden is their best option.

Biden and Trump remain neck-and-neck in polling of the race, despite the concern from Democrats. Trump leads Biden by 0.6 percent nationally in The Hill/Decision Desk HQ average of polls.