Power of Trump's endorsements faces test in 12 key US midterm primaries

Former US President Donald Trump is trying to demonstrate his power over the Republican Party with more than 150 endorsements of candidates in midterm elections that will determine control of Congress for 2023 and 2024.

Twelve key picks -- including some against incumbent members of his party -- will show Trump's influence.

Primary elections in the weeks ahead will test Trump's sway with Republican primary voters, though only Nov. 8 will show how many Trump-backed candidates can win office.

JD Vance wins primary

* US Senate seat for Ohio vacated by retiring Senator Rob Portman

* 8 November election

Trump-backed Vance triumphed in a crowded May 3 Republican primary and is favored to win in November against Democrat Tim Ryan, currently a US Representative for Ohio, although some political observers expect a stiff challenge from Ryan.

Vance is best known as the author of best-seller "Hillbilly Elegy" which documented the descent of factory towns in states like Ohio into poverty and drug abuse. He has styled himself as an angry populist in the Trumpian mold, seeking to shed his prior reputation as a Trump critic.

Upcoming races:

Ted Budd

* US Senate seat for North Carolina vacated by retiring Senator Richard Burr

* 17 May Republican nomination contest

Ted Budd, a rank-and-file member of the House of Representatives, had little statewide name recognition before he sought the Republican nomination for what is expected to be a tight race in November. Even with Trump's endorsement, Budd has trailed former North Carolina Governor Pat McCrory in public opinion polls for much of the race, though in recent polling Budd has taken a wide lead.

Mehmet Oz

* US Senate seat for Pennsylvania vacated by retiring Senator Pat Toomey

* 17 May Republican nomination contest

Oz is a celebrity doctor whose public image took a blow in 2014 when he told lawmakers probing bogus diet product ads that some of the products promoted on his show lacked "scientific muster." Trump's decision to endorse Oz has divided Republican Party leaders in Pennsylvania, with a former hedge fund CEO David McCormick and conservative commentator Kathy Barnette also contenders for the Republican nomination. The three candidates have been virtually tied in several recent public opinion polls. The winner of the primary will face a Democrat in what is expected to be among the tightest races of the November elections.

Herschel Walker

* Versus US Senator Raphael Warnock of Georgia

* 24 May Republican primary

Walker, a retired football star, is favored to win the Republican nomination contest and public opinion polls already point to a close race in November against Warnock, a Democratic pastor. But Trump-endorsed Walker, who has never held elected office, has vulnerabilities including past allegations of domestic abuse. Groups backing Walker's Republican primary opponents are planning ad campaigns that argue Walker can't beat Warnock because of his baggage.

David Perdue

* Versus Georgia Governor Brian Kemp

* 24 May Republican primary

In 2021, Perdue conceded that he lost his US Senate to Democrat Jon Ossoff, but in March 2022 reversed himself, voicing false claims that the election was stolen, although the evidence of fraud that he cited was part of a case that was ultimately dismissed by a judge. Despite Trump's endorsement of Perdue over Kemp, the state's Republican governor who angered Trump by dismissing the former president's false statements about election fraud, Kemp has a double-digit lead over Perdue in polls.

Katie Arrington

* Versus US Representative Nancy Mace

* 14 June Republican primary for South Carolina's 1st congressional district

The South Carolina state representative is challenging a sitting Republican lawmaker who voted against Trump's impeachment. Mace irked the former president shortly after taking office in January 2021 when she said Congress should consider censuring Trump for his role in his supporters' assault on the US Capitol on Jan. 6, 2021. Arrington has trailed Mace in public opinion polls.

Russell Fry

* Versus US Representative Tom Rice

* 14 June Republican primary for South Carolina's 7th congressional district

Trump's pick to unseat incumbent Republican Rice, one of a handful of Republicans who voted to impeach the former leader, is a state representative whose campaign had nearly a half million dollars in the bank on March 31, pointing to a potentially competitive race with Rice.

Loren Culp

* Versus US Representative Dan Newhouse

* 2 August Republican primary for Washington's 4th congressional district

Trump's pick to challenge Newhouse is former small-town police chief Loren Culp, who in March called for the execution of a Black man accused of badly injuring a woman by throwing her down the stairs of a train station. Trump had endorsed Culp in February, angered by Newhouse's vote 2021 impeachment vote.

John Gibbs

* Versus US Representative Peter Meijer

* 2 August Republican primary for Michigan's 3rd congressional district

Gibbs, a former housing official under Trump, saw his nomination to head the US Office of Personnel Management flounder after lawmakers from both parties questioned his history of inflammatory tweets, including references to baseless conspiracy theories about Democrats and Satanism. His opponent Meijer, who voted to impeach Trump, is far ahead in fundraising. The winner of the nomination contest will face a Democrat in what is expected to be among the tightest House races in November.

Joe Kent

* Versus US Representative Jaime Herrera Beutler

* 2 August Republican primary for Washington's 3rd congressional district

Former special forces officer Kent has campaigned with far right US representative Matt Gaetz of Florida and told Oregon Public Broadcasting he held a social media strategy call with white nationalist Nicholas Fuentes, though he said he disagreed with Fuentes' "ethno-nationalism." Kent's campaign had more than $1 million in the bank on March 31, setting up a strong challenge to incumbent Herrera Beutler, who voted to impeach Trump.

Kelly Tshibaka

* Versus US Senator Lisa Murkowski of Alaska

* 16 August open primary contest

Trump is backing Tshibaka, a former Alaska state administration commissioner, to unseat Murkowski, who was one of just seven Republican senators that voted to convict Trump in 2021 on charges he incited insurrection. The Alaska contest has taken on the shade of a proxy war between Trump and Republican Senate leader Mitch McConnell, who vowed to do everything possible to help the campaign of Murkowski, one of the Senate's few moderates.

Harriet Hageman

* Versus US Representative Liz Cheney

* 16 August Wyoming at-large-district Republican primary

Trump threw his backing behind Hageman, a land-use lawyer, in September 2021, looking to punish Cheney, who was stripped of her role as the No. 3 House Republican for voting to impeach the former president on a charge of inciting insurrection. Hageman led Cheney by 20 percentage points in a December poll.