NEW YORK: The month of May brings Donald Trump the biggest test of his political clout since the end of his presidency, as candidates he has endorsed contest Republican primaries that will set the stage for November’s midterm congressional elections.

Trump-backed candidates in Ohio, Pennsylvania and North Carolina face active and well-funded challengers seeking the Republican nomination to run for US Senate. The former president has also backed a challenger to Georgia’s sitting Republican governor, who angered Trump by rejected his false claims that his 2020 election defeat was the result of fraud.

They are among the highest-profile — and in the case of the Senate, most critical for the party — of the more than 150 candidates for federal, state and local races Trump has endorsed this year. Their races will be closely scrutinized for any sign that Trump’s iron-clad grip on his party could be waning as he flirts with a possible 2024 White House run.

“It’s important for him to maintain that perception, and perhaps a reality, that he is a king-maker in the Republican Party,” said Mike DuHaime, a Republican strategist, cautioning: “The Trump endorsement is still powerful, but it’s not undefeatable.”

Victories in May by some of Trump’s more controversial Senate picks, including former football star Herschel Walker in Georgia and television doctor Mehmet Oz in Pennsylvania, would not guarantee success in the Nov. 8 general elections and missteps could allow Democrats to hold onto their razor-thin Senate majority.

Polls show that at least one of Trump’s May picks, Senate candidate J.D. Vance in Ohio, is leading going into his Tuesday primary. But Oz trails rival David McCormick ahead of the May 17 Pennsylvania primary and former Senator David Perdue lags Georgia Governor Brian Kemp heading into their May 24 matchup.