WASHINGTON — The National Rifle Association, a Ralph Reed-led social conservative group and other organizations have quietly begun pumping millions of dollars into voter-registration drives and get-out-the-vote efforts to defeat President Barack Obama and aid GOP congressional candidates.

The strategy, coupled with Republican-backed voter ID laws enacted in at least a dozen states, poses a threat to Democrats by attempting to offset or even outperform traditionally effective voter mobilization efforts by organized labor and liberal groups.

It signals that, still seven months before Election Day, both sides are escalating funding for the ground wars, which are typically carried out below the radar but could be decisive in closely divided battleground states.

"After 2008, I vowed that as far as possible within my ability I would never allow our side to be that badly out-hustled on the ground again," said Ralph Reed, the former leader of the Christian Coalition.

This year, Reed hopes to deploy another conservative religious group, the Faith and Freedom Coalition, which he founded in 2009, to register and turn out "at least half" of the 17 million evangelicals he said didn't vote in 2008.

Democrats fear that the tightened state voter identification laws will complicate efforts by liberal-leaning groups to register new voters and thus suppress turnout among minorities and students, whose backing was critical in 2008.

Democratic-allied unions such as the AFL-CIO and liberal groups, including the League of Conservation Voters and Planned Parenthood, are countering by pouring tens of millions of dollars into their own voter registration and mobilization drives.

Liberal groups are equally revved up about the importance of getting their base to the polls in November. The AFL-CIO, the huge union umbrella group, and other big unions have announced plans to spend $400 million on this year's elections — including federal, state and local contests.

Voters in many states already have been bombarded this election season with millions of dollars in television ads, largely bankrolled by conservative and GOP-leaning groups such as American Crossroads, a so-called "super" political action committee created by former Bush White House advisers Karl Rove and Ed Gillespie. American Crossroads and its nonprofit affiliate are aiming to raise $300 million and put the bulk of their resources into television spots, an indication that Republicans could dominate the political advertising in the months ahead.

And the AFL-CIO alone is aiming to register 400,000 union members who aren't registered, says Jeff Hauser, who runs political communications for the union. "Groups like Crossroads don't have the members to do voter mobilization," he said. "That's our strength."

These outside allied drives are intended to complement voter mobilization operations by the national party committees and the presidential campaigns where Obama and the Democrats have an early money and infrastructure edge.

Plainly, both sides are aiming for a big turnout this fall.

"This election is going to be won on the ground," said Chris Cox, the top lobbyist for the NRA, which has recently launched a multimillion-dollar "Trigger the Vote" registration drive that appears to be its biggest ever. "There are millions of gun owners who aren't registered."