Recognizing the threat in Iowa, the president’s re-election campaign spent more than $400,000 on TV ads in the state in May and June, according to Advertising Analytics, a tracking firm.
Democrats’ top presidential super PAC, Priorities USA, rated Iowa this month as leaning toward Mr. Trump and outside the top-six battleground states: Pennsylvania, Michigan, Wisconsin, Arizona, North Carolina and Florida. But that might change. “While Iowa isn’t currently in our spending plans, it’s a state we’re keeping an eye on,” said Josh Schwerin, a senior strategist for the group. “The fact that it’s in play shows that Biden is on offense and will have multiple paths to 270,” he added, referring to the electoral votes needed for victory.
It’s a different story in the Senate race. Democratic outside groups have booked $24.1 million to support Ms. Greenfield with TV ads through Election Day, and Republican groups are close behind with $22.6 million on behalf of Ms. Ernst.
Democrats hoping to control the Senate need to net four seats in November (or three if they win the White House since the vice president has a tiebreaking vote). Their top targets are Republican incumbents in Colorado, Arizona and Maine. Close behind are the incumbents in North Carolina and, increasingly, Iowa.
The Senate Majority PAC, the top outside Democratic group in Senate races, has lined up $13 million for TV ads in Iowa after Labor Day. It matches $12.5 million reserved by the leading Republican outside group, the Senate Leadership Fund.
“The idea that Iowa’s in play really shouldn’t surprise people,” said J.B. Poersch, president of the Senate Majority PAC, which is aligned with Senator Chuck Schumer of New York, the Democratic leader. “It came to the table this way, since the intensity of the caucuses.”
The Iowa caucuses in February may have been a fiasco when it came to counting votes, as well as an embarrassment for Mr. Biden, who finished fourth. But a year of intense organizing by presidential hopefuls in the state brought a bounty of new Democratic voters. Democrats now outnumber registered Republicans in the state by 9,000, a reversal from the 2018 midterm elections when Republicans had a 23,000-voter advantage.