Trump’s influence to be tested in Ohio’s GOP Senate primary

Former President Donald Trump‘s influence over the Republican Party will be put to the test on Tuesday in Ohio’s GOP Senate primary, where his last-minute endorsement has propelled the once-lagging candidate J.D. Vance into a tie for the lead.

Mr. Vance, author of the bestselling book “Hillbilly Elegy,” had been struggling in polls for weeks, stalled behind GOP rival and former state treasurer Josh Mandel, who held a firm lead over all seven Republican candidates and had won several high-profile endorsements.

But Mr. Vance‘s political future brightened considerably this month when Mr. Trump announced he would back Mr. Vance’s Senate bid. The...