Former White House physician Ronny Jackson is a step closer to winning a seat in Congress.

The AP projected on Tuesday evening that Jackson was winner of the House GOP primary runoff in Texas’ 13th Congressional District – in the race to succeed Republican Rep. Mac Thornberry – who’s retiring after a 25 years in office.

Jackson's victory was due in part to the strong backing he enjoyed from President Trump. He took to twitter after his victory to spotlight that he and his wife Jane “just got off the phone with @realDonaldTrump! It’s official! I am honored to be the Republican nominee for #TX13! I promise I will make you proud!”

TRUMP BACKED TUBERVILLE CRUSHES FORMER ATTORNEY GENERAL SESSIONS IN ALBAMA GOP SENATE PRIMARY

In congratulating Jackson, the president tweeted that "Ronny will be a fantastic Congressman - Will represent the wonderful people of the Great State of Texas, and the USA, very well. Proud of you Ronny!!!"

Trump had previously nominated Jackson for Veterans Affairs secretary, but the doctor withdrew from consideration after facing allegations of alcohol abuse and mishandling prescription drugs. Jackson called the charges “false and fabricated.” He and his wife moved back home to Texas after withdrawing from the nomination.

Political pundits say that the president’s tweet of support just days before the March primary helped Jackson make it the runoff election, which was delayed until July due to the coronavirus pandemic.

Jackson faced Josh Winegarner -- a lobbyist for the Texas Cattle Feeders Association – in the runoff. Winegarner had the backing of Thornberry, as well as other local endorsements.

In the runoff campaign, Jackson was aided by officials from the Trump re-election campaign, which dramatically boosted his once meager fundraising efforts. And they helped Jackson hire a professional Republican operative to run the doctor’s campaign.

Trump campaign communications director Tim Murtaugh called the victory “a clear testament to the power and value of President Trump’s endorsement and support.”

Jackson will now be considered the favorite in November in a district where Republicans hold the upper hand.

While the influence of political endorsements is always debatable, there’s little argument that the president's backing in a Republican primary can make a big difference.

While his record’s not perfect – three Trump-endorsed House candidates lost primaries in recent weeks – the president’s support is extremely influential.

One the same night that Jackson won, first time candidte Tommy Tuberville - who was backed by Trump - crushed former Attorney General Jeff Sessions in Albama's GOP Senate primary runoff.

Sessions, who served a dozen years as senator from Alabama before becoming Trump’s first attorney general in 2017, angered the president by recusing himself that year from the Russia investigation into the 2016 election.

Sessions, who was the first Republican senator to back Trump in the 2016 presidential election, was forced out as attorney general in November of 2018. Since then, he’s repeatedly served as a public punching bag for Trump.