Mehmet Oz

The five statewide primaries once again tested former President Donald Trump's influence on the Republican side — with mixed results. Here's what we learned on Tuesday.

Five states hold primaries Tuesday. The top race is in Pennsylvania, where the GOP Senate primary will be another test of Trump's influence, while Democratic voters seem to favor John Fetterman.

This month's primaries and runoffs will serve as a test of the power of former President Donald Trump's endorsements up and down the ballot.

For the state's open U.S. Senate seat, the two top Republican contenders are David McCormick and Mehmet Oz. And, as in so many GOP races this year, there's another major player — Donald Trump.

Though more Republican-held seats are up for grabs in November, Democratic struggles mean the GOP has improved its likelihood to take control of the Senate. Here are the key contests to watch.

Donald Trump is basing his support for Dr. Mehmet Oz on electability, as Republican candidates vie for the former president's support in key battleground states.