Media playback is unsupported on your device Media caption Beto O'Rourke: "We do not have the means to pursue this campaign successfully"

US Democratic presidential hopeful Beto O'Rourke has announced he is ending his campaign.

The former Texas congressman tweeted: "Our campaign has always been about seeing clearly, speaking honestly, and acting decisively.

"In that spirit: I am announcing that my service to the country will not be as a candidate or as the nominee."

Mr O'Rourke, 47, ran for president in March after losing his 2018 bid to oust Texas Republican Senator Ted Cruz.

In that Senate race, he did better than any Democrat had in Texas for decades, running a campaign that invigorated the party nationwide and drew comparisons with former President Barack Obama.

His passionate delivery along with his good looks and background as a skateboarder and a punk rocker endeared him to liberals across the country.

But Mr O'Rourke struggled to carry that energy into a White House race crowded with more than 20 Democratic candidates.

On Friday he said his campaign did not have "the means to move forward successfully".

What did Mr O'Rourke say?

Speaking in Des Moines, Iowa, Mr O'Rourke thanked his supporters, many of whom were clearly disappointed.

"How proud I am to be with you," he said.

Media playback is unsupported on your device Media caption Who is Beto O'Rourke?

Mr O'Rourke vowed to support the Democratic nominee who will challenge President Donald Trump in the 2020 race for the White House.

"We're right in the middle of this fight," he said.

In a blog post announcing the end of his candidacy, he wrote: "We confronted institutional, systemic racism and called out Donald Trump for his white supremacy and the violence that he's encouraged against communities that don't look like, pray like or love like the majority in this country."

Mr O'Rourke was highly critical of the president after a mass shooting in his hometown of El Paso, Texas, in August, describing the bloodshed as a "consequence" of Mr Trump's anti-immigrant rhetoric.

What went wrong?

As the initial buzz over his campaign began to subside, Mr O'Rourke tried to reboot his candidacy.

He began to focus on gun control, and vowed to remove assault-style weapons from private ownership, saying in one televised debate: "Hell yes, we're going to take your AR-15s."

But he could not catch up with front-runners like former Vice-President Joe Biden, Massachusetts Senator Elizabeth Warren and Vermont Senator Bernie Sanders.

Mr O'Rourke also found himself leap-frogged by another young, charismatic candidate - 37-year-old Pete Buttigieg, mayor of South Bend, Indiana.

In the latest opinion poll by New York Times/Siena College on Friday, Mr O'Rourke drew the support of just 1% of voters in the crucial early-voting state of Iowa.

Image copyright Reuters Image caption Mr O'Rourke struggled to carry the energy of his insurgent Senate campaign into a White House bid

Mr O'Rourke had been urged by donors to drop out of the presidential race and run against Texas Senator John Cornyn, who is up for re-election next year. But the O'Rourke camp reiterated in a statement on Friday night that he did not plan on standing for the Senate again.

Mr O'Rourke is not the only once-promising Democratic candidate who is struggling - California Senator Kamala Harris this week scaled back her campaign, firing some staffers and shuttering offices in another key, early voting state, New Hampshire.

From rock star to rock bottom

In just about 12 months, Beto O'Rourke went from Democratic rock star to political rock bottom.

During his 2018 Senate race, the former Texas congressman was fundraising like a top-tier presidential candidate. Beloved by Democrats across the country for his youthful energy, his passionate stump speeches became viral sensations.

His obvious political skills in his home state did not translate on to the national stage, however, where a lack of campaign organisation and an inability to stand out on a crowded debate stage cost him dearly.

Mr O'Rourke's relatively thin CV, which wasn't a concern for Democrats when he was facing conservative stalwart Ted Cruz in Texas, was also a liability in a match-up against senators and a former vice-president with extensive experience and in-depth policy knowledge.

Some presidential hopefuls can run unsuccessful campaigns and end up with an elevated stature among party faithful - with more political prospects than when they began. Mr O'Rourke, whose campaign started high and trended only downward, was not so fortunate. He may have a second act in national politics, but his 2019 effort will be an experience he will have to overcome, not build on.

Who is Beto O'Rourke?

Mr O'Rourke represented Texas' 16th congressional district for three terms before running unsuccessfully last year for the US Senate. He travelled to all of Texas' 254 counties during his Senate campaign, documenting his journey on social media, and broke Senate fundraising records by amassing more than $80m.

He lives with his wife, Amy Hoover Sanders and three children in El Paso. He has an estimated net worth of nearly $9m (£6.7m). His first name is actually Robert, but he is known by his nickname Beto - a common contraction of Roberto, which he says he picked up as a child in El Paso.

Following his November Senate defeat, Mr O'Rourke drew criticism for embarking on a road trip across the south-western US, during which he documented his travels in a blog and admitted he was stuck in a "funk".

Even supporters questioned why Mr O'Rourke was on the road, leaving his wife at home to look after their children, while other Democratic contenders were assembling staff and funding.

As he launched his campaign, he posed on the cover of Vanity Fair, telling the magazine about the White House race: "Man, I'm just born to be in it."

He later said he regretted that move because it reinforced a "perception of privilege."

After Mr O'Rourke dropped out on Friday, President Trump, a Republican, mocked him in a tweet.