Donald Trump's presidential campaign has received an official endorsement from Tulsi Gabbard - a former congresswoman who ran to be the Democratic candidate for the presidency in 2020, before distancing herself from the party.

On Monday, Trump welcomed Ms Gabbard, 43, to a stage in Detroit, in the key swing state of Michigan.

Ms Gabbard quit the Democratic Party in 2022, complaining of its "wokeness", and has since become a regular and outspoken guest on Fox News.

Meanwhile, more than 200 Republicans who served under previous presidents and party leaders have given their backing to Trump's rival, Kamala Harris.

In an open letter, former staffers for George HW Bush and George W Bush, and Senators John McCain and Mitt Romney said another Trump administration would endanger American democracy.

Ms Gabbard appeared alongside Trump to commemorate US service personnel killed in an attack in Afghanistan three years prior, using it as an opportunity to criticise the Biden administration.

Thirteen US service members and more than 100 Afghans were killed during the suicide bombing at Hamid Karzai International Airport in Kabul.

The incident occurred as American troops made a chaotic withdrawal from the country, and the Taliban returned to power.

Trump labelled it a "humiliation" that "set off the collapse of American credibility and respect all around the world".

He was joined earlier in the day by Ms Gabbard, a military veteran, at Virginia's Arlington Cemetery to remember the American lives lost.

Ms Gabbard made frequent criticisms of US military interventionism during her career in Congress from 2013 to 2021.

Appearing at Monday's event in Michigan, Ms Gabbard said she was appealing to Democrats, Republicans and independents alike to pick Trump at the ballot box in November - saying it was a matter of "saving our country and serving the people".

Her official backing of Trump marks the culmination of a remarkable political journey over the last decade that began on the progressive left of the Democratic Party.

She was the first Hindu member of the US Congress, going on to serve as vice-chairwoman of the Democratic National Committee - before resigning to endorse the 2016 presidential campaign of Senator Bernie Sanders.

Ms Gabbard ran for president in 2020, championing liberal issues like government-run healthcare, free college tuition and gun control.

But Joe Biden became the Democratic nominee that year, and went on to win the presidency. Two years later, Ms Gabbard quit as a Democrat, saying the party had succumbed to "cowardly wokeness".

By early 2024, she was singing the praises of Mr Biden's rival, Trump, who will this time compete for the White House against Ms Harris.

She warned of a growing threat to American democracy - saying this danger was posed by the prosecution of Trump by America's left-wing.

In the subsequent months, it was even speculated that Ms Gabbard could be in the frame as Trump's potential running mate for November - a role that ultimately went to JD Vance.

Since her departure from the Democratic Party she has become a regular contributor to Fox News and has been accused of spreading "promoting Russian propaganda" by officials in Ukraine.

Ms Gabbard's comments came days after Trump received the endorsement of another Democratic defector, Robert F Kennedy Jr, who last week suspended his independent campaign for the White House.

Top Democrats were quick to dismiss Ms Gabbard's endorsement.

“Rather than focusing on earning the support of hardworking Americans, Trump is more fixated on winning the backing of extremists like Gabbard and RFK Jr — and they’ll do nothing but weigh down his sinking ship of a campaign,” the party's Rapid Response Director Alex Floyd said in a statement.