Washington CNN  — 

To win back the Senate next November, Democrats need to net three seats (if they beat Donald Trump) or four (if they don’t).

The numbers – 22 Republican seats up, just 12 Democratic ones – suggest this is eminently doable. And it might be! But the actual GOP-held seats are less appealing for Democrats than you might think, with only Colorado and Arizona virtually certain to be tight contests.

All of which brings me to Monday in Iowa, where businesswoman Theresa Greenfield (D) announced that she is running against Sen. Joni Ernst (R) in 2020. Greenfield released a video touting herself as the daughter of a crop duster: “I’m a farm kid with farm kid values ready to fight for working people,” she tweeted.

Greenfield isn’t a known name nationally, or even really in Iowa. To the extent anyone in political circles knows her, it’s for her botched campaign for the state’s third district in 2018. Greenfield was forced to drop from that race after she became aware that her campaign manager had falsified a series of signatures on the petitions to qualify her for the ballot. (Also worth noting: Democrats tried to convince freshman Rep. Cindy Axne to run.) 

And Ernst doesn’t appear hugely vulnerable either. A Des Moines Register poll conducted earlier this year showed almost 6 in 10 Hawkeye State voters approved of the job she was doing – a strong rating in a political environment in which incumbents are rarely that well-regarded.

But, but, but: For Democrats to have a legitimate chance of winning back the Senate, they need to grow the playing field beyond just Colorado and Arizona. (That’s especially true when you consider Democrats have the extremely difficult task of trying to defend a seat in Alabama.) And Iowa is a prime candidate for that Democratic expansion (along with North Carolina and maybe Georgia).

While President Donald Trump carried the state by 9 points in 2016, Democrats flipped two Republican-controlled House seats and very nearly beat Rep. Steve King (R) to secure unanimous control of the four-person congressional delegation two years later. Trump’s numbers in Iowa now also look very little like they did in 2016; just 45% approved of the job he was doing in Gallup’s 2018 state-by-state polling.

Then there’s this: Trump’s ongoing trade war with China deeply affects Iowa’s farmers. An Iowa State University study estimated that total losses to the state’s farmers from the tariff tete-a-tete could be upwards of $2 billion.

All of which means national Democrats badly need Greenfield to make this a real race against Ernst.

The Point: Democrats need more races to come online to have a realistic chance at the Senate majority. And Iowa is at the top of the list.