“It’s a money bomb,” said Jim Lottsfeldt, a veteran operative in the state.

Alaska offers Democrats another path to cobbling together the three seats they need to flip control of the Senate if Joe Biden wins the presidential race. And along with races in Kansas, Montana and South Carolina, the Alaska foray represents a major offensive into traditionally red states that are more competitive because of President Donald Trump's sinking poll numbers.

The new super PAC, North Star, formed earlier this week, according to its Federal Election Commission filing, and went up on air Thursday with its first ad, which hits Sullivan on health care. The amount made it the largest spender on television in the race, though other outside groups have been there earlier.

“I think people were initially skeptical. It’s why we were kind of alone out there in investing in Alaska early on,” said Shaughnessy Naughton, president of 314 Action, a Democratic group that backs candidates with science backgrounds and has spent $2 million to boost Gross, an orthopedic surgeon. “But I think people are seeing it as a real race, and that's why we are seeing other groups start to come in.”

North Star has apparent ties to national Democrats. Its media buyer, Waterfront Strategies, is used by a handful of major Democratic groups, including Senate Majority PAC, which is run by allies of Minority Leader Chuck Schumer. The super PAC maintains its account with Amalgamated Bank, according to its FEC filing, which is a Washington-based bank used by a wide range of Democratic organizations.

A spokesperson for Senate Majority PAC declined to comment on the group. Emails sent to a Gmail address listed on North Star’s FEC filing did not receive a response. The filing also lists a website that has no contact information or specifics about the group, just a picture of mountains and one sentence: "Alaska needs a senator who knows Alaska and puts Alaskans first."

The TV ad features a woman who said she was diagnosed with breast cancer in 2014 and criticizes Sullivan over his vote to repeal the Affordable Care Act, which would have eliminated the law's protections for people with pre-existing conditions.

Republicans have responded in kind. Senate Leadership Fund, which is run by allies of Majority Leader Mitch McConnell, is adding an additional $3.7 million to the state through Election Day, Jack Pandol, the group’s spokesman, told POLITICO Thursday. This brings their total investment in Alaska to $5.3 million.

“Make no mistake – national Democrats and outside liberal Super PACs are flooding Alaska with millions of dollars in an attempt to buy this Senate seat, flip Alaska blue and retake control of the U.S. Senate,” said Matt Shuckerow, Sullivan’s campaign manager. “This has nothing to do about us, and everything to do about them. These millions of dollars in dark money – funneled through obscure front groups –– is all part of Chuck Schumer's campaign machine.”

Still, it’s adding to a massive disparity. Sullivan’s campaign has not yet released his third-quarter fundraising totals but has said they expect to be outraised and outspent by a staggering, five-to-one margin.

Scott Kendall, a veteran operative in the state who worked for GOP Sen. Lisa Murkowski and independent Gov. Bill Walker, said six weeks ago he thought Sullivan was comfortably ahead.

“This is a shootout now,” Kendall said. “Everything that happens and disrupts the fundamentals of the race, I think, Sen. Sullivan has to pivot and account for. And that's a tough place for an incumbent to be.”

Still, Kendall cast doubt on how effective the new influx in outside spending would be with the state already inundated with TV ads and absentee ballots already sent out.

“If all they do is throw up some big, loud TV ads, we're maxed out,” Kendall said. “I watch NFL football, and I'll see three Senate ads at every commercial break. Unless they're creative and find a way to authentically connect with Alaskans, I don't know how much difference this money can make.”

Democrats think it will move the needle. Julia Savel, a spokeswoman for Gross’ campaign, said in a statement that Sullivan doesn’t represent “Alaskan values” and that he can’t be trusted to do the job.

“Those in the lower 48 may have underestimated our race, but here in Alaska, folks want real change and are looking to send Dr. Al Gross to the Senate,” Savel said.

Republicans used the new influx of cash to tie Gross to the national party, hoping to peel away any support he may have for being an independent candidate. Joanna Rodriguez, a spokeswoman for the National Republican Senatorial Committee, called Gross’ campaign a “liberal scheme to mislead Alaska voters” and said he would be a “rubber stamp” for Democrats’ agenda in Washington.

Alaska has been a reliably Republican state at the federal level. Only one Democratic presidential candidate, Lyndon Johnson in his 1964 blowout victory, has carried Alaska since statehood. And Democrats have only won one Senate race since the mid-1970s: Mark Begich ousted longtime GOP Sen. Ted Stevens and served one term, before he was defeated by Sullivan in a close race in 2014.

But Alaska also has tendencies toward independence. Third-party candidates earned 12 percent of the vote there in the 2016 presidential race, as President Donald Trump’s winning vote share of 51 percent was lower than Mitt Romney’s 55 percent in 2012.

In recent years, Democrats have nominated candidates like Gross, who are registered independents but run in the Democratic primary. Though, this year, Gross and House candidate Alyse Galvin will appear on the ballot as Democrats, after state elections officials changed the ballot design to identify candidates with the party primary they won, not their voter registration.