Democratic presidential candidate Joe Biden is finding unexpected success with low-dollar online donors, with 97% of his contributors giving less than $200.

The former vice president was widely expected to do well with big-dollar Democratic donors, who have lasting loyalty to President Barack Obama's No. 2.

But many questioned whether he'd successfully raise small amounts online, a measure that is touted as a showing of grassroots support.

Democratic presidential candidate, former Vice President Joe Biden speaks during a campaign rally at Eakins Oval in Philadelphia, Saturday, May 18, 2019. (AP PhotoMatt Rourke)

Democratic presidential candidate, former Vice President Joe Biden speaks during a campaign rally at Eakins Oval in Philadelphia, Saturday, May 18, 2019. (AP PhotoMatt Rourke)

Biden has Obama's fundraising list, which was a big advantage. But his campaign said Tuesday that nearly two-thirds of their donors are new.

The campaign says donors who list their occupation as teacher or educator account for the largest professional block of givers.

The campaign's biggest fundraising day was Saturday, when it raised more than $1,000 per minute while Biden held a Philadelphia rally.