Don Beyer talks with his campaign aides after a Mt. Vernon District Democratic candidate forum to replace retiring U.S. Rep. Jim Moran in Alexandria on April 12. (J. Lawler Duggan/The Washington Post)

In the run-up to midterm congressional elections that both major parties see as crucial, Virginia is again a magnet for political donations as candidates vie for two open seats in the House of Representatives.

Republicans and Democrats are steering money in a big way toward favored candidates in Northern Virginia’s 10th and 8th districts.

Republican Barbara J. Comstock, in the 10th, and Democrat Don Beyer, in the 8th, are far ahead of their opponents in raising funds for their party nomination bids, new federal campaign disclosure reports showed Wednesday.

Comstock, a state delegate from Fairfax, has raised $761,000 since January in the race to replace Republican Rep. Frank R. Wolf, who will retire after holding that office for 34 years.

Fairfax County Supervisor John W. Foust, the Democratic nominee in that race, has pulled in $526,000 since January, raising his total to $775,000 in what is expected to be a competitive general election in November after the Republicans pick their nominee this month.

Though the district still leans Republican, “this seat is going to be in play,” said Nathan Gonzales, deputy editor of the Rothenberg Political Report, predicting that fundraising will be among the highest in the country.

Meanwhile, in the strongly Democratic 8th District, where Democratic Rep. James P. Moran (D) will retire after two decades, former Virginia lieutenant governor Beyer has raised $668,497 since January. Republican front-runner Micah Edmond raised $44,341, Federal Election Commission reports show.

The scores of supporters contributing to candidates from inside and outside Virginia include a host of well-known donors.

Donald Trump and Chicago Cubs owner Todd Ricketts each gave several thousand dollars to Comstock, records show. Vernon Jordan, a former adviser to President Obama, contributed to Beyer’s campaign. Oprah Winfrey recently appeared at a fundraiser for Lavern Chatman, who is competing against Beyer for the 8th District Democratic nomination.

Chatman, former head of the Northern Virginia Urban League, reported $279,000 in receipts since January, including $120,000 in a donation and a loan from herself.

The money pouring into the campaigns highlights the elections’ importance at a time when Republicans hope to overturn the Affordable Care Act, among other goals. Democrats seek to push through key platform issues, such as federal immigration reforms.

With Wolf retiring, Democrats see a chance to take the seat in an area that is home to federal contractors, lobbyists and other powerbrokers. GOP leaders have responded with an outpouring of support for Comstock, who is competing against five Republican candidates.

In a statement Wednesday, Comstock’s campaign noted that more than half of the money she raised since January came from individual contributors.

“In a 6-way primary, 685 of 1,205 donors contributed small dollar amounts, and that’s a powerful indication of the strength of our grassroots network,” the statement read.

The other 10th District Republican candidates have sought to build up their organizations less than two weeks from the April 26 canvass vote at selected locations across the district.

Howard Lind, former chairman of the 10th District GOP committee, raised nearly $141,000, most of which was through a loan he made to his campaign. Stephen Hollingshead, a former official with the Department of Housing and Urban Development, raised $104,000. Veteran congressional staffer Rob Wasinger reported nearly $83,000, State Del. Robert G. Marshall (Prince William) raised $55,000, and mortgage broker Marc Savitt reported nearly $14,000, records show.

In the 8th District, several Democrats who are competing against Beyer and Chatman in a June 10 primary election are neck and neck in fundraising.

Radio talk show host Mark Levine reported nearly $323,000 in receipts, of which $250,000 was a personal loan.

Alexandria Mayor William D. Euille’s campaign reported $213,971. State Del. Patrick A. Hope (Arlington) reported raising $186,534. State Sen. Adam P. Ebbin (Alexandria) raised $178,000. Del. Charniele L. Herring (Alexandria) raised $121,315, former Navy pilot Bruce Shuttleworth reported $57,188 and Virginia Tech professor Derek Hyra raised $26,048. The FEC did not show reports on file for Satish Korpe.

On the Republican side in the 8th, small-businessman Dennis Bartow lagged far behind Edmond, with $3,397 in reported receipts. Paul Haring, a former state representative from Texas, did not file a report.