Just 26 percent of voters said they were satisfied with the Democratic Party.

The discontent includes a significant number of Democrats who expressed reservations about their own party. Forty-four percent of Democrats described themselves as unsatisfied, while just 23 percent of Republicans said the same about their party.

“They’re just not fighting back hard enough in my eyes,” said Matthew Berryhill, 35, a recruiter from Marietta, Ga., a pivotal battleground area in the state’s key Senate race this year, who described himself as a progressive Democrat. “They come out with strong statements and strong words, and no action to back it up.”