Pennsylvania Governor Josh Shapiro is the overwhelming favorite to be selected as Kamala Harris’ running mate after the Harris campaign confirmed that the likely Democratic presidential nominee will be holding a rally with her running mate on Tuesday.

Shapiro — who has been on the shortlist for the Harris Campaign since Biden dropped out — is currently being given a 74 percent chance of securing the nomination on the odds-tracking site Polymarket. Kentucky Governor Andy Beshear finds himself in a distant second with a nine percent chance, while Minnesota Governor Tim Walz is being given a five percent chance.

Both governors saw their respective odds surge after North Carolina Governor Roy Cooper took his name out of consideration. Michigan Governor Gretchen Whitmer also received vetting paperwork from the Harris campaign, though she also took her name out of consideration last week.

Shapiro is also a massive favorite on the betting site BetOnline. The Pennsylvania governor is currently a four-to-one favorite to secure the nomination, while Beshear finds himself far behind as an eight-to-one underdog.

While Shapiro has long been viewed as a favorite for the job, his odds exploded on Tuesday after a report from Politico indicated that Harris will be selecting her running mate as early as Monday. She will then be holding a rally with her running mate in Philadelphia, which is located in Shapiro’s home state.

The two candidates will then visit seven swing states in four days.

If Shapiro is indeed the candidate, the Harris Campaign will be hoping he can provide a boost in a crucial swing state. Shapiro has enjoyed high favorability ratings throughout his first term as Pennsylvania governor and is seen as a rising star in the Democratic Party.

As Shapiro’s stock rises, he is facing significant pushback from the progressive wing of the party. One letter signed by nearly 50 progressive leaders pointed to Shapiro’s “shortcomings as a national candidate,” and urged the vice president to consider Beshear or Walz instead.

“With the compressed timeline ahead of us to defeat the Trump-Vance-MAGA threat, we simply cannot afford any setbacks,” the letter said.