Bernie Sanders’ campaign says he has raised more than US$4 million in the 12 hours since announcing his 2020 U.S. presidential campaign.

The Vermont senator said Tuesday that nearly 150,000 individuals had contributed to his Democratic bid.

Previously, the biggest first-day fundraiser in the race had been California Sen. Kamala Harris, who raised US$1.5 million in the first 24 hours of her campaign.

Sanders stunned the Democratic establishment in 2016 with his spirited challenge to Hillary Clinton. His campaign helped lay the groundwork for the leftward lurch that has dominated Democratic politics in the era of President Donald Trump.

The question now for Sanders is whether he can stand out in a crowded field of Democrats who embrace many of his policy ideas and who are newer to the national political stage.