Republican presidential candidate Donald Trump arrives for a news conference at the Trump National Golf Club, Tuesday, March 8, 2016, in Jupiter, Fla. (AP Photo/Lynne Sladky)

Who are the lawmakers who have endorsed Donald Trump for president?

Capitol Hill’s Trump caucus is a group of just five Republicans, but it still has time to grow. Trump, after all, is running against the GOP establishment (though he made some overtures after wins Tuesday night in Hawaii, Michigan and Mississippi), so there’s some street cred that comes with a lack of approval from Washington pols. But that could change as Trump claims more delegates in the GOP primary contest and the The Donald seeks backing from lawmakers — or they rush to join what looks like a winning team.

The lawmakers who have endorsed Trump appear to have little in common apart from their political party and their preference for The Donald in 2016. They hail from California, the South and the Northeast. They were elected at different times. And they range in public stature from conservative rock stars to anonymous back-benchers.

Here’s your guide to the five lawmakers who have endorsed Trump so far, including a former Jeb Bush supporter and the so-called “vaping congressman”:

1. Rep. Chris Collins (R-N.Y.)

Collins made headlines on Feb. 24 as the first lawmaker to publicly back Trump. Complimenting Trump’s business experience, Collins said the mogul’s message about restoring American greatness echoed his own campaign speeches.

“Donald Trump has clearly demonstrated that he has both the guts and the fortitude to return our nation’s jobs stolen by China, take on our enemies like ISIS, Iran, North Korea and Russia, and most importantly, re-establish the opportunity for our children and grandchildren to attain the American Dream,” Collins said in a statement. “That is why I am proud to endorse him as the next president of the United States.”

The decision can appear strange given that Collins first backed former Florida governor Jeb Bush in the Republican presidential primary. (Bush and Trump — candidates that were, in many ways, polar opposites of one another — feuded until Bush left the race on Feb. 20.) Collins, 65, is a businessman-turned-politician who was elected in 2012 to represent western New York state. He received a 48 percent rating on Heritage Action for America’s congressional scorecard, which grades lawmakers on how they vote on matters important to conservatives (the House Republican average is 63 percent).

2. Rep. Scott DesJarlais (R-Tenn.)

DesJarlais, a physician by trade, is the Trump supporter whose congressional career has been most tarnished by personal scandal. After the three-term lawmaker said Feb. 29 he cast a ballot for Trump in early voting, National Review ran with this headline: “America’s Worst Congressman Endorses Donald Trump.”

Elected in 2010, DesJarlais represents parts of rural Tennessee. He has an extremely conservative voting record, earning a 92 percent score from Heritage Action. But his reputation on Capitol Hill is more heavily defined by the controversies that dominated his 2012 reelection campaign, including revelations that he had extramarital affairs with several patients and colleagues and a report that he pressured his mistress to have an abortion.

“I believe Donald Trump is the candidate best poised to make America great again,” DesJarlais said in a statement announcing his endorsement.

3. Rep. Duncan Hunter (R-Calif.)

Hunter was elected in 2008 to replace his father, Duncan L. Hunter, in representing San Diego County, Calif. (The elder Hunter launched an unsuccessful bid for president.) Like Collins, Hunter endorsed Trump on Feb. 24 after the businessman won the Nevada caucuses. Before that, he was perhaps best known for vaping during a congressional hearing (see above) and a heated exchange with then-Army Chief of Staff Gen. Ray Odierno in 2013.

Immigration is a big issue for Hunter, 39, a former Marine whose district is close to the U.S.-Mexico border. A Hunter bill cracking down on so-called sanctuary cities passed the House last July. He has a 72 percent rating from Heritage Action.

“We don’t need a policy wonk as president. We need a leader as president,” Hunter told Politico.

4. Rep. Tom Marino (R-Pa.)

Marino, who backed Trump on Feb. 29, is perhaps The Donald’s least-well-known congressional supporter. Elected in 2010, the 63-year-old represents central and northeastern Pennsylvania and was once U.S. attorney for the state’s Middle District. In the House, he has mostly kept a low profile and is not typically identified as one of the chamber’s more conservative Republicans. (On Heritage Action’s scorecard, he earned a 53 percent, below the House GOP average.)

His public appearances have become much more frequent since he endorsed Trump. Marino’s campaign Twitter feed is awash in photos of his pro-Trump television and radio hits. “Donald Trump is saying what the voters agree on and what the voters are feeling,” Marino told Politico Feb. 29, calling his endorsement decision “one of my life-changing moments.”

5. Sen. Jeff Sessions (R-Ala.)

Sessions is by far the best-known of Trump’s Capitol Hill backers, and his endorsement for the businessman came as a surprise to many who though the Alabaman might throw his lot in with Ted Cruz. Sessions announced his support for Trump at a rally on Feb. 28, citing Trump’s support for strict measures against illegal immigration.

“Politicians have promised for 30 years to fix illegal immigration. Have they done it? Donald Trump will do it,” Sessions said in Madison, Ala. “I’ve told Donald Trump this isn’t a campaign, this is a movement.”

Gaining support from a prominent immigration hardliner only helped Trump. But pundits have wondered whether Sessions, who was first elected in 1996, might regret his decision given Trump softened his position on H1B visas last week.

Sessions was a U.S. attorney in Alabama, as well as the state’s attorney general, before his election to the Senate. He has a grade of 82 percent from Heritage Action, higher than the 61 percent average among Senate Republicans.