Democrats as of Monday have outspent Republicans on advertising in the Wisconsin Senate race, $93 million to $69 million, according to AdImpact, which tracks campaign ad spending. Baldwin’s campaign accounts for more than a third of all Democratic spending on ads, while Hovde has been more dependent on outside groups.

News signs of a tightening race in Wisconsin are flashing warning signs for incumbent Democrat Sen. Tammy Baldwin as she looks to fend off a challenge from Trump-backed Eric Hovde, giving