WASHINGTON (AP) – A well-funded independent political machine with ties to Republican strategist Karl Rove on Monday signaled it was ready to spend almost $15 million on ads in four states with competitive Senate races – and that spending is expected to rise.

American Crossroads super PAC and its affiliated nonprofit, Crossroads GPS, bought $9.4 million in ad time in North Carolina, Colorado, Alaska and Arkansas between now and August. The groups also reserved another $5.5 million in Alaska for late-fall ads.

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The heavy spending was certain to help Republicans, who need to win six seats to capture the Senate majority. It was also a sign that outside groups – and their deep-pocketed patrons – would hold huge sway over November’s elections.

The Crossroads ads were set to start Tuesday in North Carolina, where almost $3.5 million will be spent on a two-month blitz against Sen. Kay Hagan, one of Democrats’ most vulnerable incumbents. In Colorado, where Democratic Sen. Mark Udall faces a challenge from Republican Rep. Cory Gardner, another $2.3 million was set to blanket ads starting a month later.

In Arkansas, the super PAC planned to spend $880,000 on ads starting June 3. The affiliated non-profit Crossroads GPS was set to start spending $875,000 on ads a week later.

The non-profit arm, which does not disclose its donors, plans a $900,000 ad blitz starting June 6 against Alaska Sen. Mark Begich, an incumbent Democrat whom Republicans see as vulnerable. American Crossroads super PAC, which does disclose its donors, also reserved $5.5 million for Alaska ads from Sept. 8 through Oct. 26.

“Karl Rove’s dark money special interest group spent $63 million last cycle in contested Senate races and the effort was a colossal failure, as they lost almost every single one,” Democratic Senatorial Campaign Committee spokesman Justin Barasky said.

Barasky said the spending was designed to promote an “anti-middle class agenda aimed at benefiting billionaire special interests.”

Crossroads spent heavily on races in 2012 and came up short; 11 of the 13 Senate races where Crossroads spent money were won by Democrats, and GOP presidential nominee Mitt Romney failed to defeat President Barack Obama.

In all, American Crossroads spent more than $116 million between Jan. 1, 2011, and Dec. 31, 2012. During the peak of the 2012 campaign, American Crossroads spent $42 million between Oct. 18, 2012, and Nov. 26, 2012.

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But the group largely went dark in 2013 and spent just $600,000 during the first three months of 2014.

After a stretch of anemic fundraising, the Crossroads super PAC raised more cash in March than it did during the previous 14 months combined to help establishment-minded candidates. The group in March resumed fundraising and brought it almost $5.2 million and reported it had more than $6.3 million in the bank.

That haul came from three organizations and 21 individuals. The largest donation – $2 million – came from former Univision owner Jerry Perenchio. A trust tied to Oklahoma coal executive Joseph Craft III gave $500,000, as did Arkansas-based investment manager Warren Stephens and Kentucky-based self-storage mogul B. Wayne Hughes.

Aides cautioned its April fundraising would not be as impressive.

The group got its start under veteran GOP strategists Rove and Ed Gillespie, who is now running for the Senate in Virginia. Its leaders now include Steven Law, a former executive at the U.S. Chamber of Commerce, and Carl Forti, a former adviser to Romney and Capitol Hill Republicans.

It is one of establishment Republicans’ favorite outside groups because of Rove’s reputation as President George W. Bush’s political adviser and a consistent presence as a pundit on Fox News Channel.

(© Copyright 2014 The Associated Press. All Rights Reserved. This material may not be published, broadcast, rewritten or redistributed.)

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