Lest there was any doubt, Donald Trump still has “it” – the ability to shape the outcome of a hot political race.

Before the former president endorsed J.D. Vance for the open U.S. Senate seat in Ohio, the author of bestseller “Hillbilly Elegy” was languishing in third place. Then, boom: Last month, Mr. Vance got the coveted Trump nod – and rode that to yesterday’s primary win with 32% of the vote, good enough in a crowded field.

What’s remarkable is that Mr. Vance, a Yale Law grad and venture capitalist who grew up poor, was once a vocal “Never Trumper.” Back in 2016, he called Mr. Trump “cultural heroin” and “a moral disaster.” By 2021, apparently eyeing the Senate race, Mr. Vance was saying “yes” to a southern border wall and “no” to all abortions, and bashing the “fake news” media.

At a recent Vance rally, Mr. Trump appeared almost tickled by the fact that his endorsee used to bad-mouth him. The Ohioan’s response: “He’s the best president of my lifetime.” Now, Mr. Trump has Mr. Vance right where he wants him: favored to win in November – and owing his budding political career to the former president.

Elsewhere, not all Trump primary endorsees are riding so high. In Georgia, at Mr. Trump’s behest, former GOP Sen. David Perdue is taking on incumbent GOP Gov. Brian Kemp, for refusing to overturn the Georgia election results in 2020. But Mr. Perdue is trailing badly. In Pennsylvania, Mr. Trump’s choice for the Republican Senate nominee – Dr. Mehmet Oz of TV fame – is competitive, but not a shoo-in.

Clearly, Mr. Trump loves playing kingmaker. And in Ohio, he showed that he’s still powerful. But the next few weeks may also show the limits of that power.