Republican presidential candidate Marco Rubio had harsh words for GOP front-runner Donald Trump, while suspending his campaign at a rally in Miami, Fla., on Mar. 15. (Video/Reuters; Photo/AP)

MIAMI — Marco Rubio — the youthful Cuban American senator once seen as the standard-bearer of a more inclusive Republican Party but who struggled to excite voters — suspended his campaign for president Tuesday night after badly losing his Florida home state primary, sending mainstream Republicans scrambling again in their urgent mission to stop Donald Trump.

Rubio’s decision marked an embarrassing blow to dozens of prominent elected officials and donors who backed him. His departure narrows the GOP field at the moment to three: Trump, Texas Sen. Ted Cruz and Ohio Gov. John Kasich.

“America is in the middle of a real political storm, a tsunami, and we should have seen this coming,” Rubio told supporters in announcing his departure from the race, saying the “politics of resentment” that swamped his campaign. “But I chose a different route and I’m proud of that.”

The conclusion of Rubio’s bid follows a dismal primary record in which he won only three contests and trailed far behind Trump and Cruz. Rubio is not running for reelection for his Senate seat, leaving his future cloudy.

Rubio built his campaign on an optimistic and forward-looking “new American century” theme meant to convince voters that he was fresh and likeable — and that his opponents were stale and less relatable to everyday Americans.

The Fix's Chris Cillizza breaks down why Marco Rubio was never going to be president. (Peter Stevenson/The Washington Post)

But his campaign proved to be badly out of step with a restive Republican electorate that gravitated to the angriest candidates in the pack: Trump and Cruz. Rubio failed to adapt to the prevailing mood; he never seemed sure about how to deal with Trump’s unlikely rise and late-race efforts to take on him and Cruz fell short.

He also lacked a concrete base of supporters. Polls consistently showed he was the second choice for many voters — a role he seemed content to play, wagering that he would be poised to capi­tal­ize as the field narrowed. He pitched himself to Christian conservatives, defense hawks and suburban centrists, all while staking out hard-right positions on issues such as abortion and gay marriage. He treated each of the four early states as equal priorities. He tried to be many things to many people.

Rubio’s decision to ambush Trump in a late February debate and fling personal insults at him in the days afterward was a pivotal moment in his campaign. After an initial burst of attention, the bottom fell out in a series of nominating contests as voters abandoned a candidate who had long banked on his broad likability to lift him to the top.

“Hostility works for some people. It doesn’t work for everybody,” Trump said last week about Rubio.

Rubio spent the closing days of his campaign hyper-focused on Florida, where he first arrived on the national political scene in 2010 as a tea-party star who felled a popular governor in the Republican primary for the U.S. Senate. But Rubio remained far behind Trump in most polls, and his final events in the state had a wistful and funereal quality similar to the last days of another failed 2016 candidate, former Florida governor Jeb Bush.

Sen. Marco Rubio, R-Fla., speaks during a campaign rally at Palm Beach Atlantic University in West Palm Beach, Fla., on Monday. (Paul Sancya/AP)

Once regarded as a rising star in his party — Time Magazine dubbed him the “Republican Savior” in a 2013 cover story — Rubio’s political future is now uncertain. Some see him as a potential vice presidential nominee or a Florida gubernatorial hopeful in 2018.

Throughout his presidential campaign, Rubio couldn’t shake a boom-and-bust cycle that prevented him from becoming a breakout star. He launched his run with a well-received speech at Miami’s historic Freedom Tower, where the federal government once processed Cuban immigrants fleeing the regime of Fidel Castro. But then he hunkered down to focus on fundraising, leaving only a light footprint in the early nominating states during the summer and disappointing prospective supporters eager to see more of him.

In August, Rubio emerged as the star of the first debate and won rave establishment reviews in others that followed. But he repeatedly followed up his strong showings on stage with a quiet presence on the campaign trail, leading even some supporters to question how hard he was willing to work.

A stronger than expected third-place showing in Iowa on Feb. 1 gave Rubio a boost heading into New Hampshire, which voted eight days later. Then came disaster: During a Feb. 6 debate, New Jersey Gov. Chris Christie mocked Rubio for mechanically repeating himself. Democrats piled on, dispatching staffers to follow him around dressed as robots. Rubio finished a disappointing fifth in the Granite State.

He resurrected his campaign in South Carolina, where he opened himself up to the press, landed the endorsement of popular Gov. Nikki Haley and studiously stayed on message. He finished second to Trump and ahead of Cruz, who his aides felt they effectively branded as a dishonest candidate.

South Carolina would be the final place Rubio would have anything to celebrate. In the more than two dozen contests after that, Rubio notched just three victories — in Minnesota, Puerto Rico and the District of Columbia — falling way behind Trump in the delegate tally.

In a Feb. 25 debate, Rubio went hard after Trump, a choice that may have sealed his fate. After avoiding a fight with the front-runner for months and hoping to hold his fire until the field narrowed, Rubio unleashed an uncharacteristic rush of attacks. He deepened them over the next three days, hitting Trump for his spelling errors on social media, accusing him of using spray tanner and calling out Trump’s “small hands” as suggestive of his manhood.

The following Tuesday, Rubio won just one state while Trump won seven and Cruz scored three wins. A week later, his showing was even worse. In Michigan and Mississippi, he finished last and was shut out of winning any delegates.

Rubio’s campaign team, a small and tight-knit group that prided themselves on not talking about its strategy to the media on the record, operated under the belief that Rubio’s skills as a candidate were its best assets and that through exposure to enough voters, he would win over Republican voters.

They also banked on his personal story — he often told supporters he was the son of a bartender and a maid — and his general election pitch would carry him across the finish line in the GOP primary.

But it never really worked. Marta Hernandez, 70, a supporter who came to see Rubio campaign last week near Miami, expressed regret over that.

“It’s disappointing that people haven’t been able to see his worth,” Hernandez said.

Ed O’Keefe in Miami contributed to this report.