(CNN)Michael Bloomberg invested almost $1 billion into his short-lived presidential campaign. A single Silicon Valley donor fueled a super PAC that tried to rescue Sen. Elizabeth Warren's bid for the Democratic nomination. Small-dollar donors warmed to former Vice President Joe Biden.

And President Donald Trump and his allies continued to build a massive war chest for the general election.

Biden raised more than $18 million in February -- twice the amount his campaign had collected the previous month, and the former vice president entered March with a little more than $12 million remaining in his campaign account.

And that was before his sweep of victories coast to coast this month solidified his political comeback. During the CNN-Univision debate earlier this week, Biden indicated that his campaign already had brought in $33 million in the first two weeks of March.