Former President Donald Trump on Tuesday faces the strongest test yet of his ability to shape a new generation of Republicans as GOP primary voters in Pennsylvania and North Carolina decide whether to rally around his hand-picked choices for critical U.S. Senate seats.

As this year’s midterm primary season enters its busiest stretch with races also unfolding in Kentucky, Oregon and Idaho, Trump is poised to notch several easy wins. In North Carolina, U.S. Rep. Ted Budd is expected to best a packed field of GOP rivals, including a former governor. And in Pennsylvania’s GOP race for governor, far-right contender Doug Mastriano was already leading before Trump backed him over the weekend.

But Trump’s preferred Senate candidate in Pennsylvania, Mehmet Oz, has divided conservatives who are typically in lockstep with Trump. Some are suspicious of the ideological leanings of the celebrity heart surgeon who gained fame as a frequent guest on Oprah Winfrey’s talk show, but has been attacked by millions of dollars of TV ads from another rival, former hedge fund CEO David McCormick. That’s benefited Kathy Barnette, a conservative commentator who faced little scrutiny for most of the campaign before resonating in the final stretch with a fierce message opposing abortion in all circumstances.

Trump, who has held campaign-style rallies with Oz, insists he is the best candidate to keep the Senate seat in Republican hands in the fall. Given his level of involvement in the race — including a virtual event on Oz’s behalf late Monday — a loss would be a notable setback for the former president, who is wielding endorsements as a way to prove his dominance over the GOP ahead of a potential 2024 presidential run.

Democrats, meanwhile, have their own high-profile primaries. In Pennsylvania, progressive Lt. Gov. John Fetterman has dominated the Senate race but was forced off the campaign trail by a stroke. The 52-year-old Fetterman remains hospitalized, though he said he is expected to make a full recovery.

In North Carolina, Cheri Beasley is the clear front-runner in her 11-candidate primary for the Democratic Senate nomination. If she prevails in November, Beasley would be the state’s first Black senator — and just the third African American woman ever elected to the chamber.

Tuesday’s contests could ultimately determine how competitive the general election will be this fall, when control of Congress, governor’s mansions and key elections posts are up for grabs. That’s especially true in the perennial political battleground of Pennsylvania, where some Republicans are already worried that Mastriano is too extreme to woo moderates who are often decisive in general elections.

“There’s definitely some concern in large factions of the party,” said Pennsylvania Republican strategist Vince Galko. “Especially those in the suburban areas.”

A Barnette victory might potentially hand Democrats a Senate seat, making the GOP’s effort to retake the chamber much harder.

More fundamentally, Tuesday’s primaries could test voters’ commitment to democratic principles. Barnette is running even further to the right than Oz and participated in the January 2021 rally that turned into an insurrection at the U.S. Capitol.

Then there’s Mastriano, who was also outside the Capitol during the mob attack and would appoint Pennsylvania’s chief elections official if he becomes governor. He has pledged to take the extraordinary step of requiring voters to “re-register” to vote — even though that’s barred by the National Voter Registration Act and likely violates significant protections under federal, and possibly state, law.

“We’re going to start all over again,” Mastriano, who has barred reporters from his campaign events, said at a recent debate. He’s made Trump’s lies about widespread electoral fraud costing him the presidency a centerpiece of his campaign — and has even been subpoenaed by the House committee investigating the Capitol riot following his efforts to name a slate of alternate Electoral College electors in Trump’s favor.

Trump’s safest bet on Tuesday might be Budd, who has overcome a slow start to emerge from 14 Republican primary candidates, including former Gov. Pat McCroy, as a favorite in North Carolina’s Republican Senate primary.

“Trump is the most important factor,” said David McLennan, a political science professor at Meredith College in the state capital of Raleigh, who also noted that another conservative group, anti-tax Club for Growth Action, has paid for pro-Budd advertising. “Trump’s endorsement turned the tide for him.”

While much of the attention during the opening phase of the primary season has focused on Trump’s grip on the GOP, the contests also serve as a referendum on Biden’s leadership of the Democratic Party. In the president’s native state of Pennsylvania, U.S. Rep. Conor Lamb, a moderate in the mold of Biden, is at risk of being trounced by Fetterman.

Known for his hulking, 6-foot-8 stature and tattoos, and for championing causes including universal health care, Fetterman has appealed to many Democrats with an outsider image — and that could hold despite his health scare.

Another race testing Biden’s national appeal with Democratic primary voters comes across the country in Oregon. That’s where the president used his first endorsement of the midterm season to back incumbent Democratic Rep. Kurt Schrader against progressive challenger Jamie McLeod-Skinner.

But Trump’s influence on GOP primaries stretches far wider.

In Idaho, Trump-endorsed Lt. Gov. Janice McGeachin is attempting to unseat Republican Gov. Brad Little. McGeachin issued executive orders banning mask mandates during the height of the pandemic when Little was out of state.

The former president’s support may also swing U.S. Rep. Madison Cawthorn’s race to keep his seat from North Carolina despite recent blunders, and political novice Bo Hines’ efforts to win the House nomination for a seat representing a district covering parts of Raleigh and points south.

Tuesday even features a Kentucky lawmaker seeking reelection who benefitted from a Trump reversal. The former president is now praising as a “first-rate Defender of the Constitution” Republican U.S. Rep. Thomas Massie — just two years after he suggested the Republican should be removed from the GOP for opposing $2 trillion in COVID-19 relief funding.

(AP)