By MATTHEW BROWN, Associated Press
BILLINGS, Mont. (AP) — Outside groups and individual donors have poured more than $45 million into Montana's U.S. senate race as President Donald Trump prepares a third trip to the Big Sky state in his crusade to unseat two-term Democratic Sen. Jon Tester.
The race is on pace to be the most expensive in Montana history, and it's been driven by Trump's apparent personal interest in Tester's defeat and his efforts to ensure Republicans keep power in the Senate.
Republican challenger and Trump loyalist Matt Rosendale trails far behind in fundraising. But he's stayed competitive with $14 million spent by deep-pocketed conservative groups on his behalf, largely on ads attacking Tester on guns, immigration and taxes, according to an Associated Press review of spending reports.
Tester says it's a case of outside interests trying to influence Montana politics. But he also has out-of-state backers: Political committees representing conservation groups, hospitals and banks.
Trump targeted Tester for defeat after the Democrat made allegations public that derailed the president's Veteran Affairs nominee, Ronny Jackson.
Trump plans a Thursday campaign rally for Rosendale at the Missoula airport — the latest in a parade of White House visits to Montana that have included Vice President Mike Pence and the president's son, Donald Trump, Jr.
Montana backed Trump by 20 percentage points in 2016. Rosendale, currently serving as state auditor and insurance commissioner, has staked his campaign on a bet that those voters will come out for him in November.
"One challenge for Tester is Montana's getting more polarized, just like the rest of the nation, and also becoming more Republican," said Jeremy Johnson, a political analyst at Carroll College in Helena, Montana. "But it's also a Democratic year. I'm not sure if that will balance out or not."
The race could soon surpass the state's previous most costly election in 2012, when $47 million was spent leading up to Tester's narrow win over former U.S. Rep. Denny Rehberg.
Outside spending in this cycle already exceeds $25 million, according to the AP's review. That figure includes more than $1 million spent by groups that favored Rosendale and attacked his GOP opponents in the June primary.
Between the two candidates, Tester holds a commanding advantage in fundraising, with $17 million brought in so far this election cycle and $1.8 million in the bank as of Sept. 30, according to campaign filings submitted this week to the Federal Election Commission.
Rosendale has brought in about $3.7 million and was down to $622,000 in cash by Sept. 30, the filings show.
At some point, said Johnson, the political analyst, the money imbalance can get lost in the wash, amid the flood of advertisements now saturating voters' mailboxes and television screens and the websites they visit.
But Montana State University analyst David Parker said Tester's cash lead is significant, because candidates typically get better rates when buying advertisements than outside groups.
"Tester, as a result, can have more penetration and control his own message," Parker said. "The outside groups — the money goes less far — and is overwhelmingly negative. You have to tell your own story in the way you want to tell it. Tester can, Rosendale can't."

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