GOP-allied Groups Spending Big On Senate Races WASHINGTON - Republicans' clear shot at winning control of the Senate is attracting tens of millions of dollars from GOP-allied outside groups eager to spend on a surer bet than a White House race with a resurgent President Obama and an unsettled GOP field. Republicans need to capture four Democratic seats to grab the majority and Democrats have all but conceded one -- Nebraska -- where Sen. Ben Nelson decided against a third-term bid in the heavily GOP state. Control of the Senate will hinge on tight races in Massachusetts and Nevada, where Democrats see their best chances of unseating two of the newest Republican senators Scott Brown and Dean Heller; Montana and Missouri, where Democrats Jon Tester and Claire McCaskill won narrowly in 2006, and open Democratic seats in Virginia and Wisconsin, according to Republicans, Democrats, campaign consultants and lobbyists. By the numbers, the odds heavily favor the GOP; Democrats are defending 23 seats, including six open seats and one independent, to the Republicans' 10. "Republicans are well-positioned to pick up Senate seats, and the message from our candidates will be a simple one -- if you want a check-and-balance on the Obama agenda and to restore fiscally-responsible, pro-jobs policies in Washington then you can start with a Republican-controlled Senate," Sen. John Cornyn, R-Texas, chairman of the National Republican Senatorial Committee, said in a statement. But eight months to Election Day, Democrats are expressing more optimism about their prospects of keeping the majority. Obama's steadily improving standing with the electorate, signs of a healthier economy and housing market and the lack of clarity in the highly divisive GOP presidential field are energizing Democrats. The current Senate breakdown is 51 Democrats, 47 Republicans and two independents who caucus with the Democrats "I know when I took this job a year ago, most people felt it was really mission impossible, that the economic climate, the number of folks that we had up, was going to make it virtually impossible," Sen. Patty Murray, D-Wash., chairwoman of the Democratic Senatorial Campaign Committee, said in an interview. I think that has changed dramatically in a year. Obviously it is still a tough climate, we have a lot of races, but we have really seen Democrats doing well in their individual states. Obama's deep-pocketed campaign and its expected spending in battleground states such as Nevada, Virginia, New Mexico, Ohio and Wisconsin is certain to lift Democratic candidates down ballot. The respective campaign committees also have the money to boost their nominees, with the Democrats reporting $15.4 million cash on hand at the end of February and the Republicans $13.4 million. The Democrats will need it -- and more -- as groups like the U.S. Chamber of Commerce and American Crossroads are spending millions earlier than ever on high-priced television ads. The Chamber is running ads in eight Senate races -- Ohio, Montana, Wisconsin, Virginia, Indiana, Hawaii, Missouri and North Dakota -- and 12 House races that hit more than 40 media markets, including the expensive Washington region. Republicans and Democrats estimate the buy at $10 million; the Chamber will only say eight figures but does describe the effort as unprecedented in its 100-year history. Some ads criticize Democrats like Tester and Virginia's Tim Kaine for backing the "$1 trillion Obamacare," the derogatory term used to describe the president's health care overhaul law. Others praise Republicans like George Allen, also in Virginia, for a pro-business record during his time in the Senate. "We absolutely see a huge opportunity," Rob Engstrom, national political director for the Chamber, said of the possibility of a Senate shift. Protect and advance -- protect our gains in the House and advance our interests in the Senate. We have a real opportunity in the Senate with very strong candidates who understand the business community. The Chamber usually waits until after Labor Day to jump into the campaign fray -- not this time and not alone. State and local chambers have joined the effort, a somewhat unusual step on national races and federal policy that undercuts the expected criticism of outsider groups trying to influence state elections. In the coming months, the Chamber is expected to surpass the $30 million-plus it spent on the 2010 midterm elections, the first campaign since the landmark Supreme Court ruling opened the door to corporations and unions to spend money on elections. "We're not going to wait for the environment we're given," Engstrom said. We want to shape the environment now. The outside groups also talk to each other -- legally. The Chamber aired 10 days of ads against McCaskill and the Karl Rove-inspired American Crossroads challenged the Democratic senator as well in a concerted attempt. On Thursday, McCaskill, who had $4.8 million cash on hand at the end of December, responded with a commercial in her defense that highlighted the criticism and included the line, "They're not from around here, spending millions to attack and attack." "There's no doubt we're going to be outspent," Murray said. But as Claire or any of our other candidates will tell you, we're not going to be outworked. And I think Claire's message in her campaign is exactly right. That it's outside groups coming in and trying to influence the people of her state. American Crossroads is a super PAC and Crossroads GPS its sister advocacy non-profit. In 2011, Crossroads GPS spent more than $7 million on issue ads in Nebraska, Montana, Massachusetts, Virginia, Ohio, Florida and Missouri that were tied to the raging debate in Washington over deficit cutting and raising the nation's borrowing authority. Nebraska's Nelson faced one of those ads. All total this year, American Crossroads has set a goal of raising $240 million to be spent on the presidential race and Senate and House contests. Recently, as Bob Kerrey weighed whether to pursue the open Nebraska seat, American Crossroads spent $30,000 on five days of radio ads skewering the former Democratic governor and senator. The ad cast Kerrey as a carpetbagger and poked fun at his time in New York as former president of the New School in Greenwich Village who "thought about running for mayor of New York City." It was just a small taste of what he could expect if he returned to Nebraska to seek the Senate seat. Kerrey decided against running, saying, "I have chosen what I believe is best for my family and me."