The party is placing a surprisingly large bet on the real estate executive to take on first-term GOP Sen. Joni Ernst in a bid to expand their path back to the Senate majority. If Greenfield wins the June 2 primary, she’ll face Ernst in a state that’s turned against Democrats since 2012, when Barack Obama carried it for the second time.

The closing weeks before the primary have brought a flurry of activity: Democrats’ leading super PAC has already spent $6 million on television ads to boost the previously unknown Greenfield’s positive image, and another super PAC is spending $1 million attacking one of her opponents. The intervention has rankled the other Democratic candidates, who say the Washington establishment is trying to smother their chances.

Iowa looms as a potential blockbuster on the Senate map — a contest Democrats need to put firmly in play as part of their takeover strategy. It’s not yet a top-tier race on the level of Arizona or North Carolina, but Democrats say they can win despite Iowa’s lurch to the right in recent years, including Ernst’s 2014 victory and Donald Trump’s decisive win in 2016.