WASHINGTON — President Trump’s re-election campaign has ramped up its fund-raising this year, bringing in $20.2 million, while investing heavily in cultivating a wide base of small donors, according to reports filed Sunday afternoon with the Federal Election Commission.

Mr. Trump’s campaign apparatus spent nearly $8.2 million through the end of last month, with more than 60 percent of that going toward low-dollar fund-raising tools such as solicitations delivered via social media, email, direct mail and telemarketing, the reports show.

The reports were filed by Mr. Trump’s campaign and two joint committees it formed with the Republican National Committee: Trump Victory Committee and Trump Make America Great Again Committee.

The committees also spent $863,000 on legal fees as Mr. Trump, his campaign and associates continue to deal with a handful of legal fights, as well as the special counsel investigation into Russian meddling in the 2016 campaign.