Several closely watched House primaries on Tuesday are testing party loyalty, ideological divisions and the strength of former President Donald Trump's influence. In Kentucky's Fourth District, Representative Thomas Massie is facing a fierce challenge from Ed Gallrein, a farmer and retired Navy special operations veteran backed by Trump. Massie has broken with the president on key votes, prompting sharp attacks, and polls suggest a tight race.

In Pennsylvania's Seventh District, one of the nation's few true swing seats, four Democrats are competing for the chance to challenge first-term Republican Representative Ryan Mackenzie. The district could play a pivotal role in determining control of the House. The candidates reflect a range of backgrounds and strategies, highlighting broader debates within the party about how best to win back competitive districts.

Meanwhile, Pennsylvania's heavily Democratic Third District features an intraparty contest shaped by divisions over immigration and Israel. The race is also seen as a measure of Representative Alexandria Ocasio-Cortez's political influence after she endorsed one of the candidates. In Kentucky's Sixth District, an open seat has drawn strong Democratic contenders in a potentially competitive race.

Adding to the uncertainty, Alabama's primaries are unfolding amid ongoing redistricting disputes, with some contests delayed until later in the summer, raising questions about voter confusion and turnout.