RadioOnFire.com - The invisible primary, also known as the money primary, is coming into focus. Of the wide slate of Democrats angling to run for the White House in 2020, five presidential hopefuls so far have shared their first-quarter fundraising totals. The results, which covered the period between Jan. 1 and March 31, are due to be filed by April 15, according to Federal Election Commission rules. But a trickle of President Donald Trump’s would-be challengers are already posting their results publicly. The five candidates who have shared their recent campaign totals so far are just as diverse as the broader Democratic field. Just two of them — Bernie Sanders of Vermont and California’s Kamala Harris — are currently U.S. senators. The others are former House member and Senate candidate Beto O’Rourke, South Bend, Ind., Mayor Pete Buttigieg and entrepreneur and free-money advocate, Andrew Yang. At the bottom end of the fundraising spectrum, Yang said his campaign has raised $1.7 million. Sanders, whose galvanizing 2016 campaign gave eventual Democratic nominee Hillary Clinton an unexpected run for her money, led the pack with a whopping $18.2 million, according to his campaign.