NRA endorses McCain in Arizona Republican primary

The National Rifle Association endorsed John McCain Thursday in Arizona's Republican Senate primary.

The endorsement was a significant boost for McCain, providing high-profile support for his conservative credentials as he tries to shake a primary challenge by former U.S. Rep. J.D. Hayworth.

Hayworth has attacked McCain's record on gun rights, saying the four-term Senator has supported restrictive legislation.

Hayworth touts an endorsement from Gun Owners of America, a smaller gun-rights lobbying group.

The NRA endorsed McCain in three of his four previous runs for the U.S. Senate, but it stayed out of his race in 2004 against a little-known Democrat.

The organization endorsed Hayworth in at least six of his seven U.S. House races.