Democratic Senate candidate Bruce Braley and his mother, Marcia, visit with seniors at the Polk County Seniors Center in Des Moines on Thursday. (Matea Gold/TWP)

Bruce Braley, the Democratic congressman who is locked in a tight fight for a Senate seat here, stopped by a senior center on a drizzly fall morning with his 85-year-old mother, a homemade peach pie and a hopeful demeanor.

“My mom taught me at a young age that you don’t show up somewhere without food,” he said cheerfully Thursday after carrying his pie from table to table to chat with regulars at the Polk County Senior Center.

But Braley will need more than pie to sweeten the impression that many Iowans have of him amid a barrage of slashing television ads that have dominated the state’s airwaves.

“All we’re seeing is the ads,” Howard Zuck, 81, a retired printing press operator, said as he waited for Braley to arrive. Zuck, like many seniors here, is a registered Democrat, but the attacks on Braley have made him feel uneasy about the eight-year congressman. “I don’t know what to think,” he said, “I really don’t.”

Carol Celia, a 68-year-old retired food services worker who was sitting nearby, is also torn: “Because they just run each other down, I don’t know who to vote for, I really don’t.”

Republican Joni Ernst speaks with an attendee during a campaign stop in Davenport, Iowa, on Sept. 25. (Daniel Acker/Bloomberg)

The conflicted feelings among Democrats about their Senate nominee speak to the tough fight Braley faces in his effort to succeed fellow Democrat Sen. Tom Harkin — a race that many once viewed as Braley’s to lose. After a series of missteps and a strong performance by his Republican opponent, state Sen. Joni Ernst, the race is now a nail-biter.

The GOP has grown increasingly bullish about its chances. A Des Moines Register poll last weekend showed Ernst, a lieutenant colonel in the Iowa National Guard, with a 6-point lead over Braley, who is a lawyer.

Ernst and her allies have had an advantage on the airwaves in recent weeks, according to a report by the Wesleyan Media Project. Pro-GOP groups have sought to make the most of a recorded comment Braley made at a fundraiser early this year in which he appeared to dismiss longtime Sen. Charles E. Grassley (R-Iowa) as a “farmer.” They also have gone after Braley’s absences from House Veterans’ Affairs Committee hearings and a dispute Braley had with a neighbor over her wandering chickens.

American Crossroads, a pro-GOP super PAC co-founded by strategist Karl Rove, announced Thursday that it is extending its television campaign another week, bringing its total spending in Iowa to $4.5 million.

“I think that Braley is in real trouble,” five-term Iowa Gov. Terry Branstad (R) said in an interview. “I just really feel this race has really turned in the last three weeks.”

Democrats maintain that the Senate race is tied — a situation, they admit, that is not ideal.

“My sense is that this election is still up for grabs,” Harkin said Thursday as he worked the room with Braley. “Obviously, I wish it were Braley way ahead, but the situation, I think, is that it’s neck-and-neck.”

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“Honestly, Joni Ernst ran a good campaign,” Harkin said.

As for Braley, “there’s been some stumbles,” the senator said. “But I think in the last three or four months, his campaign righted itself, and I think he’s running an excellent campaign now.”

Braley said Thursday he has taken responsibility for his mistakes. “We all say things that we regret,” he said.

The congressman said that he is focused on spending the final month of the race reaching as many voters personally as he can.

“I’ve known from the very beginning this was going to be a close and competitive race,” Braley said.

At the senior center, he escorted around his mother, Marcia Braley, showing off the peach pie that she made and noting proudly that she is still working as a substitute teacher.

During brief remarks, Braley again referred to his mother as he took a subtle swipe at his opponent: “When it comes to protecting Social Security and Medicare, the most important person I have to worry about is sitting right there at that table. That’s why, as your next senator, I will never vote to privatize Social Security and turn your hard-earned money over to Wall Street investment bankers.”

In a statement, Ernst spokeswoman Gretchen Hamel said that “Joni will protect Social Security for seniors like her parents, and save it for her kids’ generation by finding a bipartisan solution that won’t raise the retirement age.”

Harkin said he thinks Braley’s final push, along with a strong Democratic get-out-the-vote effort, will get him over the line.

“You’re into the area in October where people are going to be thinking about their future — which one of those two is really better for my future and my kids’ future,” he said. “And I think that’s where Braley and his campaign will surge in.”