Our state’s super wealthy social changers are at it again. Two years after their money helped make charter schools possible, the Ballmers, the Gateses and Nick Hanauer are using some of their loose millions to try to tighten gun laws in Washington.

They’ve made six- and seven-digit contributions to the campaign for Initiative 594, the measure on the November ballot that would expand the state’s background check law to cover most gun sales conducted at gun shows and online.

Their checks went to the Washington Alliance for Gun Responsibility, whose strategists will, sometime after Labor Day, start spending the dough on television commercials claiming wider use of background checks will bolster public safety without infringing on anyone’s Second Amendment rights.

The alliance can afford to wait because it is already getting a boost from a million-dollar ad campaign paid for by its nonprofit alter ego, the Center for Gun Responsibility.

Since Aug. 8, the center has run dozens of 30-second commercials as part of an “education” campaign dubbed “Background Checks Make A Difference.” The effort is set to end Sept. 5.

The ads stress the value of background checks for enhancing public safety but never mention the ballot measure that its political self is promoting. What’s nice about this campaign finance nuance is it also allows the Center for Gun Responsibility to keep secret the source of its money.

Center spokeswoman Molly Boyajian noted in an email that the nonprofit has received “gifts from local individuals, partner organizations, foundations and our national partners.”

One of those partners is Everytown for Gun Safety, founded by Michael Bloomberg, the super rich ex-mayor of New York. He’s pledged to spend boatloads of money in every corner of the country to help enact tougher gun control laws and elect pro-gun control lawmakers. I-594 fits his investment profile perfectly.

While billionaires soak up attention for their prodigious checks, where is the National Rifle Association in all of this?

The NRA does have a political action committee to oppose I-594. But its coffers are pretty much empty. A significant infusion would be needed if the venerable organization intends to deliver a serious counterpunch.

The NRA did contribute $25,000 to its PAC in July then spent most of it on staff, probably to have them survey the landscape. They couldn’t have liked what they discovered.

An Elway Poll in July found 70 percent of voters — many of them in the vote-rich Pugetopolis — “inclined” to back Initiative 594. Three months earlier, in April, an Elway Poll found the level of support at 72 percent.

Things could turn quickly. They did in 1995 when voters initially embraced a gun control-type measure then rejected it. Of late, the state’s electorate has been in the mood for reshaping society in ways the government won’t. They’ve privatized liquor and legalized marijuana, charter schools and gay marriage.

Last year, voters seemed primed to pass a food-labeling initiative until opponents shelled out $22 million to successfully defeat it.

The NRA can’t fork out that kind of money, nor must it. Neither can it hope to succeed on its reputation alone.

NRA leaders must decide whether it is worth trying to convince voters in one state in the far corner of the country to defeat an initiative, or focus on keeping members of Congress from changing the background check law for the nation.

The next few days will be very telling.