COLORADO SPRINGS — Mayor Michael R. Bloomberg of New York and the billionaire philanthropist Eli Broad have each donated hundreds of thousands of dollars. The National Rifle Association is buying political advertisements. New York’s junior senator sent a fund-raising e-mail. And the election has attracted news coverage from as far away as Sweden.

All this over a homegrown campaign to oust two Democratic state senators who provided crucial support for a package of strict new state gun control laws. As the recall elections — the first of their kind in Colorado’s history — draw closer, the race has swelled from a local scuffle into a proxy battle in the nation’s wrenching fight over gun control.

Over all, both sides have dedicated about $2 million to the campaigns, most of it in support of the two senators: John Morse, the president of the Colorado Senate, and Angela Giron, who represents the Southern Colorado city of Pueblo. That might not seem large compared with the multimillion-dollar governors’ races that can be commonplace across the country these days. But the money and the attention have transformed an off-year campaign that started with homemade signs and volunteers collecting signatures in grocery store parking lots.

Voters say they are being bombarded with telephone calls and pamphlets, radio and television commercials. Each day seems to bring a new procedural battle: over the language on the recall ballot, how the vote will be conducted or which candidates will appear as possible replacements. Mr. Morse, who represents Colorado Springs, and Ms. Giron each have one Republican challenger on the ballot.