US Democrat Beto O’Rourke has said he is running for president in 2020.

The former Texas congressman sent a text message to TV station KTSM on Wednesday afternoon confirming the news that he will seek the Democratic presidential nomination.

He wrote: “I’m really proud of what El Paso did and what El Paso represents. It’s a big part of why I’m running. This city is the best example of this country at its best.”

Mr O’Rourke was little-known outside his hometown of El Paso until he challenged Republican Senator Ted Cruz last year.

He got within three percentage points of upsetting Mr Cruz in the nation’s largest red state and shattered national fundraising records while using grassroots organising and social media savvy to mobilise young voters and minorities.

The announcement ends months of intense speculation over whether he would try to translate his newfound political celebrity into a White House bid.

Mr O’Rourke must prove whether the energy he brought to the Texas campaign will resonate on a much larger stage.

For all the buzz associated with his candidacy, the former three-term congressman has not demonstrated much skill in domestic or foreign policy.

“This is going to be a positive campaign that seeks to bring out the very best from every single one of us, that seeks to unite a very divided country,” Mr O’Rourke said later in a video announcement with his wife. “We saw the power of this in Texas.”

Mr O’Rourke joins a large and unsettled 2020 field in which his fundraising prowess, bipartisan optimism, south-western Texas charm and anti-establishment attitude could quickly make him a political force.

His lack of governing experience could hurt, but President Donald Trump’s rise suggests that the US electorate might welcome a charismatic outsider.

Although he is not among the first wave of Democrats to jump into the race, Mr O’Rourke enters with strong national name recognition.

A onetime guitarist for an El Paso punk band called Foss, Mr O’Rourke boosted his already considerable non-political street cred in the Senate race with a viral video showing him skateboarding across a restaurant car park. His trademark black-and-white “Beto for Senate” signs became hipster must-haves last year in some parts of Seattle, Los Angeles and Brooklyn.

Mr O’Rourke refused donations from outside political groups and shunned pollsters during his Senate campaign though he is not completely sworn off polling for a presidential run.