Ed Gillespie speaks to the crowd on stage during Mitt Romney's campaign election night event on Election Day 2012. (Matthew Cavanaugh/Getty Images)

Longtime Republican operative Ed Gillespie made his campaign against Sen. Mark R. Warner official Thursday, launching a bid to unseat the popular Democrat by casting him as a fiscally reckless supporter of the Affordable Care Act.

Gillespie — the former lobbyist, Republican National Committee head and aide in the George W. Bush White House — announced his effort in muted fashion, eschewing a news conference in favor of a simple video in which he introduced himself and made his case for why Republicans should nominate him and why Virginians should deprive Warner of a second term.

“I’m running for Senate because the American dream is being undermined by policies that move us away from constitutional principles of limited government and personal liberty,” Gillespie said, adding that if he had been in the Senate instead of Warner, the health-care bill “would not be law today.”

Republicans are hoping that the campaign will be anything but low-key and that Gillespie’s candidacy will put what could have been a backwater race on the map of battleground contests — with fundraising totals and grass-roots enthusiasm to match.

Jennifer Duffy, senior editor at the nonpartisan Cook Political Report, said the race will be well-funded simply because Gillespie and Warner are both adept at raising money, with extensive networks of powerful friends and donors. But that doesn’t necessarily mean the contest will be a magnet for cash from outside groups — nor that Gillespie’s entrance automatically makes it close.

“Virginia is a pretty purple state,” Duffy said. “So any credible — emphasis on ‘credible’ — opponent is going to get [a percentage] somewhere in the 40s. The question is, if Gillespie gets to, say, 46, how hard is it for him to get those other four points?”

Decisions by outside groups to weigh in probably will be based partly on whether the race looks competitive, and partly on whether they think they can get enough bang for their buck. Virginia, Duffy noted, is an expensive place to advertise — more so than some other states that have competitive Senate races. Gillespie’s entrance prompted the Cook Report to shift its rating of the Virginia race from “Solid Democrat” to “Likely Democrat.”

In a statement issued Thursday, Warner didn’t even acknowledge Gillespie by name.

“I am asking Virginians to rehire me to keep fighting for bipartisan, common sense solutions to create jobs, get our fiscal house in order and ensure that all Virginians have a fair shot at economic opportunity,” Warner said, adding: “I look forward to putting my independent, bipartisan record up against whichever candidate the Republicans nominate at their convention in June.”

The Democratic Senatorial Campaign Committee was more blunt, calling Gillespie “a career lobbyist with a partisan history of slash-and-burn politics that divides Virginians.”

Republicans will choose their nominee at a convention in Roanoke. Two other Republicans — Shak Hill, a Centreville financial planner, and Howie Lind, a former Pentagon official and lobbyist from McLean — have launched campaigns, but a handful of conservative activists are trying behind the scenes to recruit a more high-profile candidate who can challenge Gillespie from the right at a convention.

Though Gillespie has worked over the years to develop solid relationships with many conservative groups, some activists are put off by his role with Karl Rove in creating American Crossroads, a group that often supports establishment GOP candidates over tea-party-backed challengers.

In the general election, Warner will benefit from the extensive voter files and on-the-ground expertise developed by the Obama campaign during its 2008 and 2012 victories, and it will be enhanced by the deep-pocketed operation of Terry McAuliffe during his successful governor’s bid last year.

Republicans in the state have acknowledged that their ground game has lagged behind that of Democrats, though they insist they are catching up. And Gillespie, as the former chairman of the Republican National Committee, knows the territory.

“Ed has a credible voice on the issues, and people know he can run a grass-roots campaign,” said Dan Allen, a Republican campaign consultant. He added that Gillespie — who has also been viewed as a potential 2017 candidate for governor — “wouldn’t have jumped into the race” if he didn’t think he could win.