CHARLESTON — A national GOP group and a Manhattan hedge fund manager helped fuel the party’s election gains in West Virginia’s House of Delegates, contributing to a $500,000 deluge in last-minute ads separate from the $5.1 million spent by this year’s legislative candidates, the final round of campaign finance reports show.

Voters increased the Republicans’ share of the 100-seat House from 35 to 46 delegates last month. The GOP also picked up 3 seats in the state Senate, bolstering the party’s ranks to nine of 34 members. The Republican campaign strategy has at least some Democratic officials taking note.

“We’re going to have to make some changes or we’re going to lose our majority in the House,” said Pam Van Horn, executive director of the West Virginia Democratic Legislative Council. “In order to play, we’re going to have to change the way we do things, is my opinion.”

The Republican House inroads followed around $215,000 in ads, mostly direct mail flyers, launched two weeks before the election by several Republican-allied political action committees. These 11th-hour appeals to voters targeted 24 House seats, either by attacking Democratic candidates or promoting the GOP nominees.

A new group, the House GOP PAC, spent about half that amount, according to its postelection filing. Its donors included the campaigns of the state’s congressional Republicans, Reps. David McKinley and Shelley Moore Capito. Virginia House Speaker William Howell gave $10,000 and was among several out-of-state contributors.

The Republican State Leadership Committee provided $35,000. The national GOP “super PAC” devoted heftier funds to legislative candidates elsewhere, including at least $357,000 in Kentucky, for instance, and $715,000 in New Mexico.

Sean Fieler of New York’s Equinox Partners contributed $25,000. Fieler donated more than $510,000 during this election cycle to Republican super PACs, party committees and candidates, as well as to New York’s Conservative Party. Fieler helps lead several organizations that advocate a return to the gold standard for U.S. monetary policy, according to his postings on their websites. Fieler has also been active on social conservative issues through such groups as the National Bible Association and the Institute for American Values, according to their websites.

The House GOP PAC also received $25,000 from James Laurita, an executive with Morgantown-based coal operator MEPCO. Laurita has been a director of the West Virginia Family Policy Council, a leading opponent of same-sex marriage in the state. But Laurita also contributed to Democratic legislative candidates this year, campaign finance filings show.

House GOP PAC treasurer Dan Greear, a former Republican legislator, did not respond to requests for comment Friday.

The pro-Republican independent ads came as well from the Washington, D.C.-based GOPAC West Virginia, which spent around $54,000, and the West Virginia Republican Legislative Council, which spent around $41,000. These groups and the House GOP PAC all hired a Pennsylvania firm, Red Maverick Media, for at least some of their campaigns. So did the Eastern Panhandle Freedom Fund, which similarly attacked Democratic legislative candidates in the election’s closing weeks, and at least four of the Republican House nominees.

Democratic-affiliated PACs, meanwhile, spent less than $29,000 on independent ads. Those were mostly focused on aiding several unsuccessful Senate candidates, including defeated incumbent Sen. Mark Wills of Mercer County. Democratic candidates instead received ad support from labor union PACs, which spent at least $130,000 on direct mail targeting roughly the same array of House seats as the Republican-aligned PACs.

“I think it’s something that we’re going to have to look at as a party, or that our friends are going to have to look it,” Van Horn said of the independent expenditure campaigns. “From my perspective, we didn’t have the money to compete with the Republican Party, and the money they received from out of state.”

Van Horn’s group, formed to protect the party’s majority in both chambers, receives dues from Democratic legislators. In return, it offers to help them develop talking points and design ads, among other campaign services. The DLC was to some degree involved in all 11 House seats the Democrats lost, Van Horn said.

The Republican who defeated Wills, auto dealer Bill Cole, spent the most of any legislative candidate this year with more than $282,000. Cole loaned his campaign $190,000 of that. With nine of the 17 Senate seats up this year uncontested, the median spending by candidates for that body was $37,000.

Another Republican, John McCuskey, spent the most among House candidates, nearly $100,000 for his successful bid to join a redrawn four-seat district representing Kanawha County. Median spending among all House candidates topped $15,500. Both figures include spending on the May primary. McCuskey also led the chamber’s hopefuls for spending during the general election, at over $71,300, while the median spending for that phase was $8,900.