JUNEAU — The National Rifle Association has decided to not endorse in Alaska’s U.S. Senate race, with a spokesman saying Wednesday that Democratic Sen. Mark Begich’s support of two Supreme Court nominees opposed by the group cost him that endorsement.

The announcement came after the group’s political arm reported in recent filings with the Federal Election Commission that it made ad buys in several prominent U.S. Senate races across the country, including Colorado and North Carolina.

In Alaska, the NRA gave Begich an A-minus rating and his Republican challenger Dan Sullivan an A-q. The “q’’ means the grade is qualified because Sullivan has no voting record, NRA spokesman Andrew Arulanandam said. Grades in those cases are based, in part, on answers provided in questionnaires. Sullivan, a former state attorney general and Natural Resources commissioner, is making his first run for public office.

Arulanandam said Begich would have gotten a higher grade and the NRA’s endorsement if he had not voted for President Barack Obama’s Supreme Court nominees, Justices Elena Kagan and Sonia Sotomayor. Both were opposed by the NRA.

On gun votes, Begich has stood with NRA members 100 percent of the time, Arulanandam said.

He noted, for example, that after a deadly school shooting in Connecticut, Begich did not bow to pressure, even from within his own party, to support tighter background checks for buyers and a ban on assault weapons. That legislation ultimately failed.

Begich said there should be a focus on improving mental health care rather than new gun control measures.

“That certainly didn’t go unnoticed by gun owners all across the country,” Arulanandam said.

Begich and Sullivan have both touted their support for the Second Amendment during the campaign. A new Sullivan ad features Elaina Spraker, who is identified as a firearms instructor and expresses frustration with Begich.

“How do you vote for Barack Obama’s anti-gun judges and still say you support the Second Amendment?” she asks. The ad ends with a picture of Sullivan helping one of his daughters as she takes aim with a rifle.

“Dan Sullivan is proud to have the support of gun owners and NRA members from across Alaska who are fed up with Mark Begich’s votes for President Obama’s anti-gun judicial nominees,” Sullivan spokesman Mike Anderson said in an emailed statement.

Begich countered that gun ownership in Alaska “means hunting to put food on the table, self-defense and recreation. One of the strongest differences between my opponent and me are our records, and my rating from the NRA reflects that.”

In weighing judicial nominees, Begich said he always considers a broad set of issues, including Alaskans’ right to privacy from government wiretapping and the need to protect the rights of Alaska’s women.

At the time of Sotomayor’s confirmation in 2009, Begich said he made clear Alaskans’ strongly held views on the right to bear arms and said he was convinced she would not be an activist judge. In 2010, Begich made similar comments about Kagan.

The National Rifle Association Political Victory Fund has endorsed Republican U.S. Rep. Cory Gardner over Democratic Sen. Mark Udall in Colorado, and Republican Thom Tillis over Democratic Sen. Kay Hagan in North Carolina.