LOUISVILLE, Ky. — His new list of potential Supreme Court picks soothed conservatives’ fears, and his embrace by the National Rifle Association guaranteed him the backing of the most committed activists on the right, as likely Republican presidential nominee Donald Trump continued to build unity within the party.
In both cases, the support is as much about antipathy toward Mr. Trump’s likely opponent, former Secretary of State Hillary Clinton, as it is about liking the billionaire businessman.
But the effect is the same: an increasingly unified Republican Party and a candidate who is saying the right things to keep them in his camp.
Mr. Trump tried to make it an easy choice for the NRA rank and file as he addressed the gun group’s annual convention in Louisville on Friday, talking up his sons’ enthusiasm for firearms, railing against gun-free zones and saying that electing Mrs. Clinton would mean kissing the Second Amendment goodbye.
“The only way to save our Second Amendment is to vote for a person that you all know named Donald Trump,” he said at the NRA-ILA Leadership Forum. “I will never let you down. I will protect our Second Amendment. I will protect our country.”
Chris Cox, who heads the NRA’s lobbying arm, openly acknowledged that Mr. Trump might not have been the first choice for everyone but told attendees that if their preferred candidate dropped out of the race, “it’s time to get over it.”
“Now, were there differences between the candidates for the nomination? Of course,” Mr. Cox said at the forum. “Are there valid arguments in favor of some over others? Sure.
“Will any of it matter if Hillary Clinton wins in November? Not one bit,” he added.
During his speech Mr. Trump also highlighted his list of 11 potential Supreme Court picks — a list that won him praise from conservative activists and pro-life advocates last week.
Pro-life groups, in particular, responded with enthusiasm to the list, and, combined with the NRA, they make up the backbone of the volunteers the Republican Party relies on to knock on doors and rally neighbors at election time.
“The right is starting to coalesce,” said Republican Party strategist Michael McKenna. “Questions about is he sufficiently conservative have been banished.”
Charlie Curie, 63, a veterinarian from Ohio, said he thinks the NRA’s endorsement will spur on gun rights enthusiasts to knock on doors or get active in the campaign in some other way.
“Honestly, in my opinion, I would pick anybody other than a Democrat,” said Mr. Curie. “And not just for Second Amendment issues — on all of the conservative issues.”
Carrie Christman from near Buffalo, New York, was hopeful the endorsement would mobilize folks. She was helping sell T-shirts with a picture of a giant bird and what appeared to be lightning bolts coming out of its talons, with the words “Trump: Shocking the establishment” on the front and “Trump 2016” and a presidential seal on the back.
“I hope it does energize the NRA members to get involved and become active — actively pursue your neighbors to actually get them out to vote,” she said.
But Tony Matuszak, who was hawking the shirts along with Ms. Christman, was skeptical.
“It’s tough to get people to freakin’ do work, man, OK?” he said. “It’s really tough to get walking boots.”
John Thayer, 62, who works in accounting in Florida, pointed out that the NRA typically saves its endorsement for after the party officially selects its nominee, and said he did think it would spur people on to do more during the campaign than simply pull a lever on Election Day.
“I was for Trump from the beginning, but a lot of the NRA people and other pro-gun people were for [Sen.] Ted Cruz,” said Mr. Thayer, who was wearing a red “Make America Great Again” Trump hat and a pin with a likeness of Mr. Trump on it.
“Now it’s just a choice, really, between Trump and Hillary, so I mean to me it’s pretty clear that if you’re a conservative, you’re going to vote for Trump,” he said.
Mr. Trump’s conservative critics have said his positions can change almost daily depending on what audience he’s speaking to or what mood he’s in. For example, in his 2000 book “The America We Deserve,” Mr. Trump wrote that he generally opposes gun control, but that he supported a ban on so-called assault weapons and a slightly longer waiting period to get a gun.
Mr. Thayer, though, said the inflexibility of other onetime candidates such as Mr. Cruz and Sen. Rand Paul is a turnoff.
“Cruz and Paul — you know, they act like they’re in a college debating club. They stake out an absolute position and then say ‘it’s this or nothing,’” he said. “And Donald Trump — he’s negotiated all his life in business. I think it’s better to get half of what you want than nothing.”
Larry Seitz, 63, a retired maintenance executive from outside Chicago, said the stakes are extremely high for the fall, and appeared concerned that many people still wouldn’t tune in to get properly educated.
“Most people don’t pay attention until eight to 10 weeks in front of the election. You know, and then they start reading the news but they haven’t paid attention to what’s going on,” he said.
Mr. Seitz said his mind’s pretty much made up as to who he’s voting for and said most of his friends are in a similar boat.
“But once they step behind that curtain, they may say one thing and do another, you know?” he said.