The assumption that Montana is an impenetrable Republican stronghold has held Democrats back from heavy spending on their candidate in the state, the folk-singing populist Rob Quist. "Our polling indicates that Donald Trump is still very popular here. It's not like the [special election] races in Georgia or Kansas, where Trump only won by 1 point or where [Kansas] Gov. [Sam] Brownback has popularity problems," Brock Lowrance, the campaign manager for Republican nominee, Greg Gianforte, told Politico in late April. "There's nothing to indicate that the winds have shifted here in the last six months."

And yet in recent weeks, Quist has narrowed Gianforte's lead to just single digits. Considering Gianforte's apparent assault on a reporter Wednesday night, Democrats might now be kicking themselves for not spending more in a state that is turning out to be far more competitive than anyone expected:

The contest in Montana, to fill the seat vacated by Interior Secretary Ryan Zinke, has drawn national attention, with both sides together pouring over $10 million into television and radio ads. But this spending in Montana's relatively cheap media markets happened almost in spite of the national Democratic Party, which has been skeptical about Mr. Quist's prospects. Democrats only began helping their nominee here reluctantly, after weeks in which Republicans hammered Mr. Quist on TV with little response. Republicans outspent Democrats more than two-to-one on television and radio, according to media buyers in both parties. [The New York Times]

Additionally, "Montana has a reputation for being a state surprisingly amenable to Democrats in a region that's not known for it," Paul Blest writes at The Week. "While a Democrat hasn't held the lone congressional seat since 1997, a Democrat has held the governor's mansion since 2005 and one of the state's two senators, Jon Tester, is a two-term Democrat."

The Democrats did put out an eleventh-hour ad Thursday featuring audio of Gianforte's alleged assault. But it could still be too little, too late: "The overall race has been an excellent representation of authentic economic populism against today's Republican Party, with its brutal domestic agenda and Government Sachs Cabinet," Ryan Cooper writes at The Week. "Whether or not Quist can eke out a victory is an important test case for whether economic populism can win in red states." Jeva Lange