DENVER—Gun-rights activists in Colorado turned in petition signatures Monday to set up the first recall in state history of a state lawmaker after he backed some of the strictest gun control measures to become law in the U.S. this year.

The opponents of Democratic Senate President John Morse said they turned in twice as many signatures as needed Monday to put Morse back on the ballot. Carting white paper boxes of petitions, the gun-rights advocates said Morse will pay for backing a series of gun control measures that were signed into law earlier this year.

“This shot will be heard around the world,” said Bill Adaska, a retired engineer from Denver who volunteered to gather recall signatures in Morse’s Colorado Springs district. “This is the race, right here, that’s going to show Washington and Chicago that when you come after our guns, we’re going to take you out.”

Adaska is referring to a gun-control package that made Colorado the first state outside the East Coast to significantly ratchet back gun rights after last year’s mass shootings in Aurora, Colo., and Newtown, Mass. The Colorado package included expanded background checks to include private and online gun sales, plus a 15-round limit on most types of ammunition magazines.

Morse backed the gun control measures, and sponsored an even stricter measure to gun owners liable in some cases for damage caused by their weapons. Morse scuttled that liability measure when it appeared it didn’t have enough support to clear the Senate.

A defiant Morse responded Monday to the recall petition by insisting he won’t resign and that national gun groups have targeted him in an effort to scare politicians nationwide away from addressing gun control.

“This turns into a national race,” Morse predicted.

Even if he loses his seat, Morse said, the gun measures were too important not to adopt after a bloody 2012. He insisted that he’s never aspired to another office and wouldn’t mind losing his political career over the gun bills.

“Keeping Coloradans safe from gun violence is very worth your political career,” Morse told reporters.

Talking about last year’s Connecticut school shooting, Morse added, “We had 20 6-year-olds shot in the face, and we have the other side arguing we should do nothing, and I’m sorry, that doesn’t cut it.”

The National Rifle Association sent a political mailer in support of the Morse recall effort. However, recall supporters insisted the effort was home-grown and conducted without national support. They hired petition gatherers, and local gun shops contributed firearms and ammunition to reward people who volunteered gathering petition signatures.

“I ran this campaign. The NRA did not run this campaign,” said Rob Harris, organizer of the recall effort. “We the people are making a stand against the people who refused to represent their constituents.”

Morse, a former police chief, is term limited and has one year left in office. If Republicans pick up his seat, Democrats would still control the Senate, in addition to the House and the governor’s office.

The Colorado Secretary of State has 15 business days to verify signatures. After that, Morse has a period of time to challenge signatures before a recall election is set. The latest possible date for a Morse recall vote would be early October.

No state lawmaker in Colorado history has ever faced a recall vote. The special election would ask whether Morse should be recalled, and if so, who should replace him. Voters would answer both questions, though the second wouldn’t be counted if Morse holds on.

Any candidate with 1,000 signatures could make that second part of the ballot, except the incumbent, opening the door for a Democratic candidate as a replacement. Democrats hold a narrow registration advantage in the district.

Gun-rights activists are still working to recall another Democrat, Sen. Angela Giron of Pueblo. Signatures in that effort aren’t due until next week.

Recall efforts against two other Democratic lawmakers who backed gun control have already fizzled for lack of support.

If this year’s efforts against Morse and Giron succeed, they would be the first lawmakers to face recall votes since Colorado adopted the recall in 1912, said Joshua Spivak, who tracks recall elections nationwide at the Hugh L. Carey Institute for Government Reform at Wagner College in New York.

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Kristen Wyatt can be reached at http://www.twitter.com/APkristenwyatt