Rep. Barbara Comstock (R-Va.) (Katherine Frey/The Washington Post)

Rep. Barbara Comstock (R-Va.) built up a commanding reserve of cash during the first three months of the year as she seeks reelection to her 10th District seat, while fellow Republican incumbent Rep. Dave Brat had a much thinner fundraising lead over several Democratic hopefuls in Virginia’s 7th District.

Comstock ended March with more than $1.8 million in cash after raising $875,488 since the first of the year, according to campaign finance reports filed Sunday and tabulated by the Virginia Public Access Project.

Her bid for a third term is drawing national attention, as Republicans fearful of a backlash against President Trump scramble to hang on to the seat in a Northern Virginia district that has turned increasingly blue. Comstock’s district stretches from the heavily Democratic Washington suburbs through Loudoun County to more conservative areas near the West Virginia line.

Democrat Alison Friedman continued to hold a fundraising lead over several other hopefuls vying to take on Comstock. Friedman, who has worked as an activist against human trafficking, reported $817,631 on hand. She raised $314,898 during the year’s first quarter.

State Sen. Jennifer Wexton (D-Loudoun), who was endorsed last month by Gov. Ralph Northam (D), had $630,707 on hand at the end of the reporting period. She raised nearly $267,345 during the three months, a period she spent primarily in Richmond for this year’s 90-day General Assembly session.

Army veteran Dan Helmer had $516,146 on hand after raising $207,008 in the first quarter. Former Obama administration official Lindsey Davis Stover had $471,956 on hand after raising $229,728. And former ­federal prosecutor Paul Pelletier had $191,294 in the bank after raising $191,191.

Alison Friedman is one of the Democrats vying to challenge Rep. Barbara Comstock (R). (Jahi Chikwendiu/The Washington Post)

Republican Shak Hill, who is challenging Comstock from the right, reported $63,401 on hand after raising $76,579 from January to March.

The quarterly report shows that Comstock followed through on her promise to reject donations she had received from Rep. Patrick Meehan (R-Pa.), who said in January that he would not seek reelection after allegations surfaced of inappropriate behavior toward a female aide.

Committees associated with Meehan had given at least $8,000 to Comstock, and she said she would donate the same amount to charities that work with women and children. According to her campaign finance report, she made $1,000 donations to eight separate charities, including the Just Ask Prevention Project, the Loudoun Abused Women’s Shelter and SafeSpot Children’s Advocacy Center.

One of the donations appeared to be a mix-up, though: Comstock reported giving $1,000 to Catholic Charities of Alexandria, then took the money back and gave it to Catholic Charities of Arlington.

Virginia’s 7th District — which reaches from north of Culpeper down through the Richmond suburbs and into the rural southern part of the state — had been seen as solidly Republican. But after two terms, Brat is facing serious competition. He reported $646,355 in cash on hand after raising $249,661 during the reporting period.

Two Democrats are battling for the nomination to oppose Brat. Former CIA operative ­Abigail Spanberger had $476,469 on hand, according to the filings, but raised more than Brat during the first three months of the year with $338,509. Former Marine Dan Ward reported $508,096 in cash after raising $233,789 for the period.

Libertarian Joe Walton and Helen Alli, who is running as an independent, are also challenging Brat but have a small fraction of his resources. Walton reported reserves of $3,287, and Alli reported $2,553.

The primaries are scheduled for June 12.

Jenna Portnoy contributed to this report.