Peer-to-peer texting broke onto the national scene in 2016 when Senator Bernie Sanders used it to organize volunteers during the Democratic primary, and Democrats in particular seem to be racing ahead with their plans to use the technology.

Volunteers for Stacey Abrams, a Democrat running for governor of Georgia this year, have sent more than 1.2 million text messages. Senator Doug Jones, the Democrat who prevailed in last year’s special election in Alabama, set up “texting banks” that sent 1.4 million texts to voters during that race. Alexandria Ocasio-Cortez, whose long-shot primary campaign defeated Representative Joseph Crowley, a 10-term incumbent in New York, used the texting app Relay to help drive voters to the polls.

Roddy Lindsay, the chief executive of Hustle, a start-up that helps organizations use peer-to-peer texting, said the texting method “gets back to the heart of what campaigns do, which is talking to people and winning hearts and minds.”

Victoria Nadel, a volunteer for Mr. Jones’s campaign last year, used the Hustle app to reach Alabama voters, reminding them to vote and where their nearest polling place was. Hustle automatically supplied each text message with a name and a number. All she had to do was hit send — which she did, hundreds of times a day.

“It’s the best tool right now for getting out the vote,” Ms. Nadel said.

Text messages are not free — most peer-to-peer platforms charge 10 to 30 cents per conversation, with discounts for large clients — but they are less expensive than printed mailers and appear to be more effective than other communication methods. Hustle, which is used by many Democratic campaigns as well as groups like Planned Parenthood and the Sierra Club, says texts sent through its platform receive responses at twice the rate of phone calls, and 36 times the rate of emails. Opn Sesame says 90 percent of text messages are opened within five minutes.

All this texting seems to translate to dollars and votes. According to internal tests done by the Democratic National Committee, voters who received text messages through Hustle as well as printed mailers donated to campaigns at an 8 percent higher rate than voters who received only mailers. And campaign officials said voters who received texts on Election Day were more likely to show up at the polls.

“We saw an increase in turnout amongst the communities we reached out via text message during the primary election,” said Priyanka Mantha, the communications director for Ms. Abrams’s campaign in Georgia.