Democrat Aftab Pureval captured national attention this summer as a rising star with a shot at unseating longtime Republican Rep. Steve Chabot in Ohio’s 1st District. But questions about irregularities in his campaign spending set off a flurry of GOP attacks that may have dented expectations.

The Democratic Congressional Campaign Committee’s last ad in the Cincinnati-area district expired Monday and other major groups are not active there, said Bob Kish, a consultant for Republican candidates who has access to reports of spending totals that are not publicly available. 

“I get the impression that they might have pulled the plug,” Kish said, adding that it would be unusual for a group to skip a day of ad spending only 15 days before the election if it still planned to invest in the race.

DCCC spokeswoman Amanda Sherman took issue with that assessment. 

“How the DCCC chooses to invest in individual races changes week by week, and we aren’t going to reveal our playbook,” she said. “Aftab Pureval is running a strong campaign that speaks to the key issues that voters in Ohio’s 1st Congressional District are concerned about, including protecting affordable health care and improving infrastructure.”

Republican groups, meanwhile, are still in the race. Congressional Leadership Fund, a super PAC aligned with House GOP leadership, currently has $730,000 invested in the Cincinnati market for ads supporting the incumbent, Kish said.

The DCCC spent around $624,000 on television ads in the district from Sept. 24 until this week, according to a source familiar with the race. 

Pureval, the Hamilton County clerk of courts, posted record-breaking fundraising totals in the first weeks of his campaign, causing speculation of an upset in a seat drawn to favor Republicans. He’s raised $3.1 million this cycle through Sept. 30, compared to Chabot’s $1.4 million. 

But his campaign has struggled amid a state inquiry into whether he used his local political campaign account to pay for a poll for his congressional campaign. Inside Elections with Nathan L. Gonzales rates the race Leans Republican. 

“You can’t blame national Democrats for recognizing the obvious: Aftab Pureval’s campaign is rudderless, under investigation, and stumbling through the final weeks of this race,” National Republican Campaign Committee spokesman Chris Martin said. 

A New York Times Upshot/Siena College poll from earlier this month found Chabot leading 50 percent to 41 percent with 9 percent undecided. Republicans were outpacing Democrats in early voting last week, The Cincinnati Enquirer reported.  

Watch: 12 Ratings Changes for House, Senate and Gubernatorial Races — 4 Toward GOP, 8 Toward Democrats