Can gun control be a winning election issue? Democrats revved up to try.

Advocates of gun-safety regulation say the public is reaching a tipping point after terrorist attacks like the ones in Orlando, Fla., and San Bernardino, Calif. But polls show voters don't see it as the most important issue facing the US.

Democrats are moving full force toward gun control as an election-year issue.

The Orlando nightclub massacre – the worst mass shooting in modern United States history – has galvanized Democrats in Congress. Just before their July 4 recess, they staged a 25-hour sit-in in the House and a talk-a-thon in the Senate to demand votes on gun legislation. They’re also targeting vulnerable Republican House and Senate seats on the issue.

Hillary Clinton, their likely standard bearer for president, is campaigning on gun-safety regulation. And the public overwhelmingly supports such measures as background checks at gun shows and preventing terrorists from buying guns.

"2016 is shaping up to be the year of gun safety in the election,” says Brina Milikowsky, chief strategy officer for Everytown For Gun Safety, the advocacy organization founded by former New York Mayor Michael Bloomberg in 2014. The group has endorsed Mrs. Clinton.

But will gun safety actually motivate voters? Will it cause them to punish opponents of “common sense” regulation and reward supporters?

That’s the key question, because America has seen versions of this story before – mass shootings, a presidential candidate for more gun regulation (Barack Obama), and favorable public opinion. And yet it is the gun-rights lobby, spearheaded by the National Rifle Association (NRA), which has had the upper hand in legislation at the state level and in Congress.

Still, advocates of gun-safety regulation feel encouraged, with many saying the country is reaching a tipping point. They describe a slow boil of anger and fear about gun deaths – now combined with terrorism. They cite a frustrating disconnect between public opinion and a nonresponsive Congress.

“There comes a time when you have to say something, we have to make a little noise, when you have to move your feet. This is the time,” said Rep. John Lewis (D) of Georgia, the veteran civil rights leader, during the House sit-in last month.

What will make a difference this year is organization and momentum, says Ms. Milikowsky. Everytown can’t match the NRA in dollars, she says, but it has people power: mayors, moms, survivors, and other supportive Americans, a total of 50,000 volunteers who will be focusing on key state races, as well as advocating for Clinton.

No longer a 'third-rail' issue?

She ticks through a list of successes at the state level in the last two years: the reelection of three governors who signed gun-control legislation – in Colorado, Connecticut, and New York; the reelection of Colorado gun-control legislators after a recall; the ouster of a couple of state senators in Oregon who had blocked expanded background checks.

Last year, gun-control supporters, including Everytown, invested heavily in the Virginia state elections. They point to the state Senate victory of Jeremy McPike, a pro-gun-control Democrat whose district includes the NRA headquarters, and the tightening of another targeted race, although their candidate lost.

“My take on 2014 and the Virginia election in 2015 is that the gun issue, which was once considered a third rail, can be an issue to run on, even on NRA turf in Virginia,” says Milikowsky.

On Friday, California Gov. Jerry Brown (D) signed a package of gun-control measures that, among other things, included expanding background checks to those purchasing ammunition, limiting the size of magazines and banning "bullet buttons" that allow shooters to more quickly change magazines, and making it more difficult to legally borrow a gun. However, Governor Brown vetoed five other gun-control bills, including one that would have made not reporting a stolen gun a crime.

Since the 2012 mass shooting at Sandy Hook Elementary School in Newtown, Conn., six states have expanded background checks to all gun sales, the most recent being Oregon and Washington, according to the Brady Center to Prevent Gun Violence. Two citizen initiatives for universal background checks will be on the ballot in Nevada and Maine this fall.

“A larger, more gradual development that we’ve seen over the years is coming to fruition now,” says Brendan Kelly, spokesman for the Brady center. “This is really starting to matter for people,” he says, citing the “historic activism” during last month’s Senate gun-control talk-a-thon, when 160,000 Americans called the Senate from every state, shutting down some senators’ lines.

While Mr. Kelly maintains that gun-regulation advocates are scoring wins on the state level, he acknowledges that Congress is a much tougher battle.

In June, eight Republicans backed a bipartisan Senate bill to prevent individuals on the no-fly list and a related list from buying firearms in a gun store. That’s twice the number of Republicans who backed a bipartisan bill to close the “gun show loophole” in the aftermath of Newtown. Neither bill, though, was able to advance despite majority support.

Meanwhile, House Speaker Paul Ryan (R) of Wisconsin is expected to allow a vote on terrorist “no fly, no buy” legislation this week. But it’s similar to an NRA-backed Senate measure that Democrats reject.

'Single-issue' voters

The tricky thing for Democrats is not only the money and organizational prowess of the NRA, but that its backers are “single-issue” voters – that is, they turn out on Second Amendment rights alone.

“They’re politically active, they're savvy, they understand the issues and they make the electoral connection to that,” says Jennifer Baker, director of public affairs for the NRA. “Draconian gun control at every level of government has really energized [people] to vote against Hillary Clinton and down the ballot.”

At the same time, the NRA highlights its successes in states such as West Virginia, Idaho, Mississippi, and Missouri, where gun-control advocates invested against “permitless carry” laws, yet the NRA, by activating its members, won the day. Before the California measures were signed into law Friday, the NRA’s 2016 tally of state gun legislation signed or enacted into law showed the NRA leading 41 to 1, compared to wins for the other side.

It can be argued that Virginia’s state election, too, produced little bang for the pro-gun-control buck. That side spent lots of money, but was unable to flip the narrowly controlled GOP state Senate, as hoped: The McPike win was for an open seat that had already been held by a Democrat.

“For the gun-rights people, I think it’s fear that their gun rights are going to be infringed upon in some massive way” that sends them to the polls as reliable single-issue voters, says Kyle Kondik, political analyst and managing editor of Sabato’s Crystal Ball.

“I don’t know what it would take for a big group of voters to come out and make decisions based on gun control,” says Mr. Kondik. “I’m not convinced it’s going to be a big driver in this election,” he says, adding that presidential elections are defined by big-picture issues, such as the economy, and in this case, the traits of the candidates.

Indeed, Gallup shows only 1 percent of Americans think gun control is the nation’s most important problem.

“Democrats haven’t been able to capitalize on a gun issue after tragedies in the past, and I don’t see why this year is any different,” says David Wasserman, who tracks House races for the independent Cook Political Report. 

His counterpart who follows Senate races says the issue is unlikely to affect vulnerable GOP senators in battleground states. "I suspect that any voter who lists gun control as one of the three most important issues facing the country wouldn't have voted for these incumbents anyway," writes Jennifer Duffy in an email.

Still, gun-control advocates remain undaunted, at least about prospects in the states. 

Everytown’s Milikowsky is especially encouraged by citizen initiatives to expand background checks. The legislature in Washington state refused to act on universal background checks, she says, but advocates wouldn’t take no for an answer. Their 2014 ballot initiative won by nearly 60 percent, including rural counties and even Republican districts.

The story is similar in Nevada and Maine, she says, with citizens getting ahead of recalcitrant legislatures.

“For nearly a generation, the gun lobby has had the field to itself,” Milikowsky says. The Washington initiative showed that “while the gun lobby can bully legislators, they couldn’t bully voters.”