“Jim Justice is a proven winner whose record of creating jobs, cutting taxes, and fighting for conservative values has made him one of the most popular governors in the country,” said Sen. Steve Daines (R-Mont.), chair of the National Republican Senatorial Committee.

Justice made his remarks this evening at The Greenbrier, his luxury resort in White Sulphur Springs, W.Va. The ballroom where Justice gave his speech was plastered with black-and-white signs that his campaign put up advertising his talking points: “Conservative Values.” “Rock Solid Behind Second Amendment.” “Most Pro-Life Governor EVER.” “Charter Schools.” “Home School.”

In a campaign video played at the event, Justice’s team touted his support of Trump and painted him as a rock-ribbed conservative.

“Joe probably won’t run if I’m running,” Justice said to a smaller crowd outside the ballroom following the announcement. But he said that if Justice isn’t the GOP nominee, then Manchin will run and win.

Manchin has said he will not decide whether he will run for reelection until the end of the year. He has also left the door open to a presidential bid.

“I am laser focused on doing the job West Virginians elected me to do — lowering healthcare costs, protecting Social Security and Medicare, shoring up American energy security and getting our fiscal house in order,” Manchin said in a statement released Thursday. “But make no mistake, I will win any race I enter.”

The National Republican Senatorial Committee played an active role in recruiting Justice. With a 64 percent approval rating, Justice is the fifth-most popular governor in the country, according to a survey conducted last year by Morning Consult.

During his speech, Justice fed up red meat to the GOP base, bashing the slogan “defund the police,” denouncing abortion, and painting President Joe Biden as senile. He did not criticize Manchin. Alongside him the whole time was his famous bulldog “Babydog.”

There was a show of support at the announcement from Justice’s friends in the Senate. Sen. Shelley Moore Capito (R-W.V.) was a featured speaker at the event, where she talked positively about Justice but declined to critique her fellow West Virginia senator. “This is about taking back the majority in the United States Senate,” she said.

Sen. Lindsey Graham (R-S.C.) also appeared at The Greenbrier, pointing to the 2022 midterms that were disappointing for the GOP.

“We’re down one in West Virginia,” he told the crowd of a few hundred. “We need help in Washington. We need a winner. We need somebody who can win in a general election.”

Before taking on Manchin, Justice must face GOP Rep. Alex Mooney in the Republican primary. The conservative group Club for Growth has vowed to spend at least $10 million on the race, and has already reported spending from its super PAC this week.

Mooney’s campaign said in a statement that “Republican primary voters will soon see that [Justice] is nothing but a Democrat in sheep’s clothing.” The congressman is launching an TV ad on Thursday that bashes Justice as a “liberal.” Justice was previously registered as a Democrat and switched parties in 2017.

“Simply put, Alex Mooney is the only proven conservative in this race and the only candidate that can beat Joe Manchin next November,” said John Findlay, Mooney’s campaign manager.

Both candidates would benefit greatly from Trump’s endorsement and are angling for that support. Mooney flew down to Florida for a congressional fundraiser on Friday — and also chatted up Trump at the event. Mooney’s campaign wants Trump to at least stay neutral if he won’t endorse the conservative congressman, according to a person briefed on the event.

In a brief interview after the campaign kickoff, Graham declined to predict whether Trump would endorse Justice. “I know he really likes the governor,” he said. “They had a terrific relationship.”

Democrats seem eager to see a messy primary. “West Virginia’s GOP Senate primary is going to be a nasty, messy and expensive fight,” said Democratic Senatorial Campaign Committee spokesperson Amanda Sherman Baity, “and whichever candidate manages to hobble out of their intraparty battle will be damaged and out of step with the voters who will decide the general election.”

POLITICO previously reported that Justice planned to launch his campaign on Thursday.

Burgess Everett, Ally Mutnick and Meridith McGraw contributed to this report.