A new poll revealed that Vice President Kamala Harris’ pool of potential running mates remains widely unknown to the public.

A new AP-NORC survey asked Americans their opinions of three candidates being considered as Harris’ potential running mate: Sen. Mark Kelly, D-Ariz., Gov. Josh Shapiro, D-Pa., and Gov. Andy Beshear, D-Ky.

There was one candidate leading in favorability among the survey’s Democratic respondents.

Kelly was found to have the highest favorability rate among those in the candidate pool, with about 45% of Democratic respondents having a favorable opinion of the senator.

About four in 10 Democratic respondents said that they still do not know Kelly well enough as a candidate to form an opinion.

According to the poll, about one quarter of Democratic respondents said they view Shapiro positively, while 16% have a negative view of him. 

Still, the Pennsylvania governor remains unfamiliar to most respondents. 

About 60% of respondents said they do not have enough information to form an opinion on Shaprio, with 57% of Democrats saying they do not know him well enough to say whether they favor him as a candidate.

The majority of adults, 74%, said they also do not know enough about Beshear to have a favorable or unfavorable opinion. 

Politico recently reported that Harris’ vetting team met privately with both Shapiro and Kelly, but the vice president has yet to make a formal announcement on her running mate.

Harris will hold the first campaign event with her vice presidential pick on Tuesday in Philadelphia, but is expected to announce her running mate in the days beforehand.

The poll was conducted from July 25 to 29 with a margin of error of plus or minus 4.1 percentage points.