MADISON, Wis. (AP) — Democratic Sen. Tammy Baldwin has raised nearly $4.4 million between April and June, up from the first three months of the year and more than four-times as much as one of her Republican opponents.

Baldwin reported the latest fundraising total Thursday. The impressive collection comes as conservative outside groups opposing Baldwin have already spent about $11 million on the race.

Baldwin has raised more than $8 million in 2018 and has more than $7.2 million cash on hand.

Republicans Kevin Nicholson and state Sen. Leah Vukmir face each other in the Aug. 14 primary for a chance to take on Baldwin. Nicholson reported earlier this week that he raised $1 million in the second quarter of the year, one-fourth of what Baldwin did. Vukmir has not yet reported her totals, which are due Monday.