Democratic presidential nominee Joe Biden has pulled in $47m in campaign donations in March alone – nearly twice the amount raised by the Republican National Committee and three times the total raised by Trump campaign.

However, while he may have narrowed the Republicans’ financial lead, the gap remains daunting. Thanks to the amount it spent on the competitive Democratic primary, Mr Biden’s campaign ended March with a net $26.4m on hand, whereas Donald Trump’s campaign boasted nearly $100m. The Republican Party also has a healthier bank account than the Democrats, counting $77.1m to its rivals’ $35.9m.

Both sides are facing unprecedented fundraising difficulties thanks to the coronavirus outbreak, which has ruled out both large rallies and in-person fundraisers with mega-rich donors.

The two are therefore focusing their efforts on courting small donors, apparently with some success. Some 40 per cent of the Biden campaign’s March take came from individual donors who have so far given less than $200 to any candidate this election cycle.

Mr Biden struggled to raise money throughout the Democratic primary, where he was consistently outraised and outspent by his rivals – not least Bernie Sanders, whose formidable base of grassroots supporters collectively donated vast sums to his campaign.

However, another candidate proved that campaign spending is far from the be-all and end-all: Michael Bloomberg, one of the ten richest men in the US, spent $936,225,041.67 on his campaign, more than half of it in February alone. He netted only 46 of the hundreds of delegates available on Super Tuesday and promptly dropped out of the race altogether.

Mr Bloomberg has consistently said he will support the Democratic effort to oust Mr Trump no matter who the nominee is, and now he is no longer a candidate he is indeed throwing millions of dollars behind the campaign.

He originally planned to set up an independent entity that would spend and organise outside the Democratic structure; however, he has now apparently scrapped that plan and instead transferred $18m in unspent campaign money to the party itself. That sum accounted for more than half of the Democratic National Committee’s total first-quarter fundraising.

Mr Sanders, meanwhile, last week sent an email to his supporters calling on them to donate to the Democratic Unity Fund, a fundraising operation set up in the early days of the primary to bring in dollars not tied to a particular candidate. With some progressive Sanders supporters still reluctant to get behind Mr Biden or doggedly opposed to him, the former candidate’s blessing could prove invaluable.