Republican candidate Marco Rubio scored a key endorsement on Tuesday from popular Sen. Tim Scott, R-S.C., who described his colleague as the GOP's best "shot" to beat Democratic presidential candidate Hillary Clinton.

Scott, the only Black Republican in the Senate, endorsed the Florida Senator in a video that was released by Rubio's campaign Tuesday. In the 50-second YouTube video, Scott said the Republican party has "one shot" to beat Clinton in the general election and "that shot is Marco Rubio," before adding, "with him as our candidate, we win."

Scott also praised Rubio as a trustworthy candidate who understands Americans.

"I am putting my confidence and my trust in Marco Rubio, because I believe that he takes us to that better future. Marco Rubio understands that here in America, it's not about where you start, it's about where you are going."

The expected endorsement came after Rubio finished third in Monday's Iowa caucus with 23 percent behind, but not far from, Ted Cruz and Donald Trump.

It also came a week after Rubio landed an endorsement from another well-respected lawmaker in South Carolina, Rep. Trey Gowdy, reports NBC News. Both endorsements will likely give Rubio a boost in the crucial early-voting state, which could lead to his first primary win.

Last month, George Pataki officially endorsed Rubio after he suspended his own 2016 presidential bid in December.

"I fear if Donald Trump is our party's nominee, then Hillary Clinton will be President," said the former New York governor in a written statement. "Fortunately, Republicans who want to win have a conservative alternative in Marco Rubio -- a person who will not only unite our party, but defeat Hillary Clinton in November."

Watch Tim Scott endorse Marco Rubio below:

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