The National Republican Senatorial Committee on Wednesday made its first independent expenditure foray into Nevada and Wisconsin, waiting until less than five weeks before Election Day to expand its advertising footprint as part of a strategy that helps ensure it has enough cash reserves to bolster underfunded candidates.

The NRSC, which would not comment on its ad strategy, had been noticeably absent from the front lines of the ad wars being waged in several Senate battlegrounds across the country, partly because friendly outside organizations have been spending significant dollars in races, allowing the committee to take a wait-and-see approach. While there is no coordination, spending from groups such as American Crossroads, Crossroads GPS and the U.S. Chamber of Commerce allowed the committee greater flexibility. 

“We have every confidence that with the combined efforts of the NRSC, our candidates and our friends on the outside, every Republican candidate in every competitive race will have the resources they need to get their message out to voters,” NRSC spokesman Brian Walsh said.

Candidates who might be in particular need of financial assistance from the NRSC down the stretch include former Govs. George Allen and Tommy Thompson, the Republican nominees in Virginia and Wisconsin, respectively.

Until Wednesday, the committee had spent about $5.3 million in IEs, according to filings with the Federal Election Commission. That’s less than half the IE total of the Democratic Senatorial Campaign Committee, which is playing more offense than expected at this stage of the cycle. But the NRSC and GOP outside groups have combined to keep a heavy presence on the airwaves across the playing field.

Through Wednesday, the DSCC had reported spending about $11 million in 10 states. That doesn’t count the ad buys the committee recently announced but had not yet reported to the FEC: $526,000 in Arizona and $410,000 in Maine, both open-seat pickup opportunities not on the landscape at the outset of the cycle.

The DSCC has also benefited from the presence of Democratic-aligned groups such as Majority PAC and its affiliate, Patriot Majority USA, which have spent heavily in tossup states and have helped push marginally competitive states, such as Indiana, into the dead center of the fight for the Senate. 

Democratic strategists said the collective efforts of the DSCC, Democratic outside groups and well-funded Democratic candidates have kept the party’s spending competitive with the GOP. Candidates get better rates on TV time purchases, which is why both committees have also used coordinated ads and transferred money directly to the candidates and state parties.

The NRSC had spent a majority of its IE money in Montana and North Dakota, two offensive opportunities in Republican-leaning states. But they’ve also spent almost $2 million in Indiana and Maine, which Republicans did not expect they’d need to defend at the beginning of the year.

Maine has been a focal point of the Senate landscape since Sen. Olympia Snowe’s (R) surprise retirement announcement in February altered the outlook of that state, kicking off the most unique race of the cycle. 

The drama revolves around former Gov. Angus King (I), who is favored to win and is expected to caucus with Democrats. National Democrats have not endorsed their own nominee, state Sen. Cynthia Dill, who has little chance of victory. National Republicans want Dill to take a greater share of the vote to help their nominee, Maine Secretary of State Charlie Summers, catch King. Both national parties have begun spending there, with the DSCC announcing its buy on Friday following an earlier move by the NRSC.

Indiana has roared onto the scene in recent weeks, though the potential for an upset became more of a possibility when Sen. Dick Lugar lost the GOP primary in May to state Treasurer Richard Mourdock, who now faces Rep. Joe Donnelly (D). The DSCC has spent $980,000 there and the NRSC has spent $713,000. Mourdock will be getting even more backing soon from the Club for Growth, which announced on Monday $500,000 in broadcast and cable TV ad buys in both Indiana and Arizona.

The NRSC’s first two IEs of the cycle were filed Aug. 31. They were earmarked for ads in support of North Dakota Rep. Rick Berg (R), who is running for his state’s open seat against former state Attorney General Heidi Heitkamp (D), and in opposition to Sen. Jon Tester (D), who is being challenged by Rep. Denny Rehberg (R). 

North Dakota and Montana are two of the three states, along with Nebraska – which the GOP is currently favored to win – that Republicans must pick up to take the Senate majority. The Senate would be split 50-50 if they’re successful in all three, and control would be decided by the outcome of states such as Massachusetts, Nevada, Virginia, Wisconsin and Connecticut.

The DSCC has already dropped $1.2 million in the Nutmeg State, and more is expected to help offset the spending advantage former WWE CEO Linda McMahon (R) has over Rep. Christopher Murphy (D). McMahon has deep pockets and has invested a lot of her own money. 

The DSCC has also spent $1.3 million in Nevada, $1.5 million in Wisconsin and close to $1 million in Virginia, where it has plenty more reserved.

The NRSC hasn’t spent anything in the Old Dominion yet but has about $5.5 million reserved. American Crossroads and Crossroads GPS, however, have already combined to spend almost $4 million in independent expenditures, which is just a fraction of the overall spending in the state against former Gov. Tim Kaine (D). The one-time Democratic National Committee chairman increased his TV time purchase to $7.5 million and has taken a lead over Allen in recent polls.

Nevada remains a close race between appointed Sen. Dean Heller (R) and Rep. Shelley Berkley (D), who joined first lady Michelle Obama for a rally in Reno on Wednesday. 

The committees have stayed off the airwaves in Massachusetts, where Sen. Scott Brown (R) made a pact with Harvard Law School professor Elizabeth Warren (D) to keep outside money out of the race.

“Not very many days left in this election and a lot of work to do,” DSCC Chairwoman Patty Murray (Wash.) told reporters Tuesday.