Former Rep. Gabrielle Giffords and her husband former astronaut Mark Kelly had lunch today with former President George H.W. Bush and his wife Barbara at their Kennebunkport, Maine home, Giffords spokeswoman Pia Carusone tells ABC News.

Giffords and Kelly are on their seven-day seven-state "Rights and Responsibilities Tour," to push for expanded background checks for firearms purchases. They are also being accompanied by some families of victims of the Sandy Hook school shooting who were with them Friday evening in New Hampshire and today in Maine.

This isn't the first time Giffords and Bush have met. When Giffords was recovering in a Houston hospital, Bush and his wife Barbara went to visit her. In her 2011 memoir with Kelly, they write that at that point in her recovery she could only say "chicken" to the former president and first lady.

Bush has an interesting history with gun control himself. In 1989, then President George H. W. Bush issued an executive order halting the importation of some semi-automatic firearms after a mass shooting that killed five children and wounded 29 others in California in January 1989. The shooter used an AK-47 assault rifle.

In 1995, the former president resigned from the National Rifle Association after the NRA compared agents of the Bureau of Alcohol, Tobacco and Firearms to "Nazis" who harass gun owners.

"Your broadside against federal agents deeply offends my own sense of decency and honor, and it offends my concept of service to country," Bush wrote in a letter to the NRA president Thomas Washington on May 3, 1995. "It indirectly slurs a wide array of government law-enforcement officials, who are out there, day and night, laying their lives on the line for all of us."

In a fundraising letter at the time NRA executive vice president Wayne LaPierre, who still holds that title, described federal agents as "wearing Nazi bucket helmets and black storm trooper uniforms" and wanting to "attack law-abiding citizens," which Bush called "vicious slander on good people."

Bush's resignation letter ended with: "You have not repudiated Mr. LaPierre's unwarranted attack. Therefore, I resign as a life member of NRA, said resignation to be effective upon your receipt of this letter. Please remove my name from your membership list. Sincerely, George Bush."

In April, the Senate defeated legislation that called for tighter background checks on gun purchases, and Giffords and Kelly made stops in some of the states with senators who voted against the measure in a bid to get them to switch their votes.

The tour kicked off Monday in Nevada, where at a shooting range in Las Vegas Giffords shot a gun for the first time since being shot in the head in early 2011. They then stopped in Alaska, North Dakota, Ohio, and New Hampshire. The goal is to apply pressure to Sen. Dean Heller, R-Nev.; Sen. Mark Begich, D-Alaska; Sen. Kelly Ayotte, R-N.H., Sen. Rob Portman, R-Ohio; and Sen. Heidi Heitkamp, D-N.D., all of whom voted against the legislation in April.

Giffords and Kelly also stopped in Maine and Sunday they plan to be in North Carolina to thank Sen. Susan Collins, R-Maine, and Sen. Kay Hagan, D-N.C., for supporting the background-check legislation.

Kelly got in some target practice in Nevada, Alaska, and went shooting in the north country of New Hampshire on the tour. The message they are sending is a clear one: they are not anti-gun, they just want what they call reasonable gun control. They are armed with their own commissioned polling in individual states, which show there is wide support for background checks in the states where senators voted against the legislation.

An ABC News poll in April found that 86 percent of Americans support extending background checks to gun sales at gun shows and online.

At a stop in Nevada, Kelly said through their "research we have found that a lot of criminals buy guns at gun shows and over the Internet and that needs to change." He added that Giffords "inspires me every day." She was almost killed in January, 2011 when a mentally ill man shot her and killed six others in her congressional district in Tucson, Ariz.

Besides going shooting, on the tour they have also stopped in a diner in North Dakota, grabbed ice cream in Ohio, threw out the first pitch at a baseball game in Manchester, N.H., and met with community leaders in all of the states trying to push their message.

In Nevada, Giffords told a crowd tougher background checks cuts across partisan lines.

"Democrats and Republicans, everyone. We must do something. Fight, fight, fight," Giffords said.

It's something Carusone, a longtime Giffords aide, also noted in an interview at the beginning of the tour, telling ABC News they will be meeting with a "coalition of unlikely allies that support commonsense gun measures," including "gun owners, Republicans, independents, hunters, all sort of people."

"We are with Republicans [on the tour who] we may disagree with on other issues, but on this issue they want bipartisanship and they want Congress to make some progress on this," Carusone said.

At least one of the senators who was in the spotlight of the tour: Heitkamp responded to the visit telling ABC affiliate WDAY-TV in Fargo, N.D., that while she does support legislation that prevents trafficking of firearms she won't be changing her mind.

"I think that is something that we could get behind if we can get some compromise but I don't see this thing coming up again," Heitkamp said.

In January, Giffords and Kelly announced the creation of Americans for Responsible Solutions, and sat down with ABC News' Diane Sawyer to discuss the initiative and mark the second anniversary of the Tucson shooting. Giffords and Kelly said the December shooting at the Sandy Hook School meant they had to do something more.

"Enough," Giffords told Sawyer.

"After the shooting in Tucson, there was talk about addressing some of these issues, [and] again after [a movie theater massacre in] Aurora [Colo.]," Kelly said. "I'm hopeful that this time is different, and I think it is. Twenty first-graders' being murdered in their classrooms is a very personal thing for everybody."

The meeting between Giffords and the Bushes was first reported by The Associated Press.