The campaign said that the service should be immediately available for subscribers to Verizon, Sprint, T-Mobile and U.S. Cellular. Other carriers — including AT&T, the nation's second largest wireless provider — are expected to enable the service soon.

The campaign said it would promote giving via text at campaign events and on online Web videos — times they believe Obama supporters would be inclined to grab their phones and make a quick donation. The service could also get big play at the Democratic convention in two weeks, with the campaign hoping to encourage new giving through the novelty of the text messaging service.

The text donations became possible after the Federal Election Commission issued a series of advisory opinions in recent months ironing out the logistics of the program. Both the Obama and Romney campaigns encouraged the FEC to allow the donations, although the Romney campaign has not yet announced plans for a similar text-based donor program.