Former Vice President Joe Biden called several supporters Tuesday to ask for their help in lining up contributions for his presidential run, according to a report from The Wall Street Journal.

A source told The Wall Street Journal that Biden reached out to "at least a half-dozen supporters" to tell them he intends to enter the 2020 race for the White House. 

Biden, who would enter an already crowded Democratic primary field, reportedly expressed concern he wouldn't be able to raise the millions of dollars in online donations right away like the other candidates. 

Democratic presidential candidate Beto O'Rourke revealed Monday his campaign raised $6.1 million online within 24 hours of announcing his White House bid. It was the most reported by any 2020 candidate, closely followed by Bernie Sanders, who raised $6 million in one day. 

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According to The Wall Street Journal, Biden is hoping to line up contributions from major donors so he can quickly raise several million dollars. 

This past weekend Biden made a verbal slip about making his campaign official, when he said he had "the most progressive record of anybody running." He quickly corrected himself, but the comment prompted frenzied speculation. 

The Wall Street Journal noted that people around Biden have cautioned that the former Vice President could still change his mind and not run in 2020.