(Reuters) – Tens of thousands of National Rifle Association members gather in Houston this weekend for the first time since the Senate rejected a plan last month to expand background checks for gun buyers, but officials say attendees will not sit back to celebrate victory.

“We view it as an opening battle in what will be a multi-year war,” said Andrew Arulanandam, a spokesman for the NRA, which lobbied against the proposal. “We’re definitely not resting on our laurels.”

Polls show more than 80 percent of Americans support expanded background checks, but the proposal to extend background checks for sales made online and at gun shows fell six votes shy on April 17 of the 60 votes needed to clear a procedural hurdle in the Senate.

The proposal, which supporters have vowed to revive, is a key part of President Barack Obama’s gun-control effort sparked by the school massacre in Newtown, Connecticut.

The vote was a sign of the influence of the gun lobby, particularly the NRA, which spent $18.6 million in the 2012 campaign cycle, according to the Sunlight Foundation. The NRA has more than 4 million members.

The NRA gathering in the nation’s fourth-largest city, which starts Friday and continues through Sunday, is billed as a celebration of the Second Amendment to the U.S. Constitution setting out the right to bear arms.

The event is expected to draw some 70,000 attendees who can stroll 400,000 square feet of displays to see the latest products from firearm manufacturers and hunting outfitters, check out wildlife art and shooting accessories, or sign up for hunting trips around the world. It will also draw protesters who plan to demonstrate for more gun-control measures such as background checks.

There will also be a Stand and Fight Rally with political commentator Glenn Beck, a country music jam featuring the Eli Young Band, and remarks from leading gun rights advocates including former Alaska Governor Sarah Palin, Texas Governor Rick Perry and Louisiana Governor Bobby Jindal.

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