MADISON, Wis. (AP) — Gov. Scott Walker is in another tight political spot, and his allies are again rushing to the Republican's rescue, powering his re-election bid and trying to keep alive his presidential prospects.
On the ballot for a third time in four years, Walker is in a tough race against Democrat Mary Burke, the former Trek Bicycles executive who has proved more formidable than his previous rivals.
A poll released Wednesday shows the race is a dead heat.
"The more these polls come out, the more people realize it's going to take a lot of hard work," Walker said in an interview before the latest numbers surfaced.
If Walker is to mount a presidential campaign, as widely expected, he first must win re-election. A loss in November could hobble him in national politics ahead of the 2016 White House race.
So big-time help is on the way.
The National Rifle Association and a Republican Governors Association-backed group, Right Direction Wisconsin, are airing about $525,000 in ads this week alone. Total GOP-leaning spending on advertising is now at close to $7 million, outpacing the Democrats' $5.4 million on the air.
Walker's allies know the drill.
The RGA spent $5 million to help elect him in 2010 and $10 million more to keep him there during a 2012 union-driven recall, when Walker became the first governor in U.S. history to survive such an effort.
Already this year, the governors' group has spent $3 million to aid Walker, and that number is expected to more than double by Election Day, Nov. 4.
Republicans say that if Walker needs more than that, he'll have it. Walker is at the top of their list of incumbents to defend.
The NRA has a $1 million ad buy booked through mid-October and could renew if the race remains tight.
In a twist, Walker's political future could rest with a potential Republican rival in 2016, New Jersey Gov. Chris Christie.
Christie heads the RGA and has opened the committee's bank accounts for Walker. If Walker were to lose, his supporters could blame Christie for cutting off the money, potentially adding to Christie's image as a political bully.
To head that off, Christie plans to campaign with Walker on Sept. 29.
Many of the RGA donors are Walker fans. Keeping him an ally is good for attracting crowds and RGA fundraising.
Big-dollar donors like Walker, too.
Koch Industries, controlled by the billionaire industrialists Charles and David Koch, has given almost $1.8 million to the governors' group so far and is its leading donor. One of the outside groups backed by the brothers, Americans for Prosperity, has hosted Walker at events and is expected to be one of his most bullish backers if Walker ran for president.
Hedge fund billionaire Paul Singer's Elliott Management is the RGA's second-biggest donor this year, with $1.3 million in donations so far. Singer organized events during the 2012 GOP convention in Tampa, Florida, for Walker to meet other Wall Street donors.
Singer is friendly with the governor and could be a major financial supporter for a pro-Walker super political action committee in 2016, just as he was for 2012 nominee Mitt Romney.
Even so, Walker's nervousness about the election is showing.
"I think it's a matter of fatigue," Walker said during a recent visit to his Madison campaign offices. "People forget but this is, at best, a purple state, probably leans historically blue."
Momentum appears to be turning to Walker's side, according to a Marquette University Law School poll released Wednesday.
In August, 59 percent of registered voters who said they are Republicans and 60 percent of Democrats said they were very enthusiastic about voting, according to the poll. But this month, the share of Republicans who said they were very enthusiastic rose to 67 percent while the Democratic number was unchanged.
Overall, Walker and Burke are essentially tied. Among likely voters, Walker had 49 percent support and Burke had 46 percent support, with a 4.1 percentage point margin of sampling error.
The poll of 589 likely voters was conducted between Sept. 11 and Sunday.
Through the first half of the year, Burke had raised $3.6 million for the race, while Walker collected almost $8.3 million.
That kind of advantage is not unusual for Walker, who beat back a costly 2012 recall rooted in his effort to take away public sector union rights.
Walker and his allies spent almost $59 million defeating the recall, trouncing the $22 million spent by Democrats.
Elliott reported from Washington.
Follow Scott Bauer on Twitter at https://twitter.com/sbauerAP and Philip Elliott at https://twitter.com/philip_elliott