Michael Bloomberg re-registers with Democrats eyeing 2020 presidential bid

'At key points in US history, one of the two parties has served as a bulwark against those who threaten our Constitution,' says former New York mayor

Michael Bloomberg has re-registered as a member of the Democratic Party, as the billionaire weighs up a 2020 presidential campaign.

The former New York mayor — who was elected in his home state as a Republican, and was also previously registered as an independent — wrote in an announcement, "We need Democrats to provide the checks and balance our nation so badly needs".

"At key points in US history on of the two parties has served as a bulwark against those who threaten our Constitution," Mr Bloomberg wrote in his Instagram post. "Two years ago at the Democratic Convention, I warned of those threats".

He added, “Today, I have re-registered as a Democrat - I had been a member for most of my life – because we need Democrats to provide the checks and balance our nation so badly needs.“

Mr Bloomberg also uploaded a photo to Twitter showing the voter registration form he used to re-register with the Democratic Party.

The move is just the latest show of support the well-liked billionaire has given to the Democratic Party with less than 30 days until the crucial midterm elections.

He’s been spending millions of dollars to support Democratic races across the country in key swing districts, funnelling resources to several Democratic candidates via a super PAC primarily funded by Mr Bloomberg. His net worth is estimated to be over $48bn.

The 76-year-old has pledged to invest $80m in Democratic congressional races this year, along with $20m to a senatorial-focused super PAC.

It remains unclear how Mr Bloomberg would fare in a 2020 race, as the Democratic Party sees a wave of progressive candidates overthrowing longtime congressional incumbents. Mr Bloomberg recently criticised liberals for their supposed opposition to strict regulatory guidelines on big banks and businesses, and has defended “stop and frisk” measures implemented in New York under his leadership.

He’s repeatedly hinted at running in 2020 as a Democrat, saying in September, “I don’t see how you could possible run as a Republican.”

In 2016, the former mayor considered launching an independent bid for president, but instead endorsed Hillary Clinton. If he chooses to run in 2020, this would mark Mr Bloomberg’s first Democratic campaign.