A view of a .45 semi-auto handgun on display at the National Rifle Association Annual Convention on May 4 in Houston. The NRA opened its annual convention May 3 in combative style, positioning itself as champion of American freedoms in the face of growing pressure for tougher gun laws.

HOUSTON — The board of the National Rifle Association will elect as its president Monday a hard-line culture warrior who has worked for decades to make the NRA a more aggressive political force.

The election of James Porter — ensured after the endorsement of outgoing President David Keene last week — is one of many defiant signals to come out of the NRA’s annual meeting in Houston over the weekend. The organization vowed to continue to fight any compromise on gun-control legislation in Congress.

“Revenge is what’s motivating the president’s unrelenting attacks on gun owners today,” Porter told the group’s meeting Saturday amid news that the NRA’s membership had grown to a record 5 million.

“Millions of Americans are becoming first-time gun owners,” Porter said. “The media calls it fear. That’s not it. It’s a sense of natural outrage that’s been building for quite some time.”

Porter, 64, a lawyer from Birmingham, Ala., who defends gun manufacturers, has been building that outrage his whole life. His father, Irvine C. Porter, was president of the NRA in 1959 — when the son says the NRA was “a glorified shooting society.” At a breakfast Friday, Porter told grass-roots organizers that they are on the front line of a “culture war.”

“He seems to come out of a mold that’s much closer to the base than David Keene,” said Josh Horwitz of the Coalition to Stop Gun Violence. Whereas Keene was a “steady hand” for the NRA amid controversy, Porter is “a complete wild card,” Horwitz said. “The world’s changing around them, and they’re hunkering down.”

The weekend also featured speeches from politicians such as Sen. Ted Cruz, R-Texas — who challenged Vice President Biden to a debate on gun violence — and the NRA’s crowd-pleasing executive vice president, Wayne LaPierre.

“We will never surrender our guns. Never,” LaPierre said. “The media and the political elites can lie about us and demonize us all they want, but that won’t stop us.”

Observers said the tone of the convention wasn’t surprising, given the debate over universal background checks in Congress, which the NRA has fought bitterly. “The rhetoric has been ramped up,” said Josh Sugarmann of the Violence Policy Center. “They’ve doubled down on their absolutism.”

As more than 70,000 people visited the weekend event — primarily for the gun trade exhibits on the floor of the Houston convention center — about 70 protesters held vigil across the street, reading the names of 3,863 victims of gun violence since the shooting in Newtown, Conn., on Dec. 14. The last name on the list: Carlos Serrano, 48, shot in a robbery while going to work Friday 6 miles from the convention.