WASHINGTON (AP) — The National Rifle Association — long seen as a kingmaker in Republican politics — is taking a lower profile in this year's high-stakes midterm campaign, a sign of the shifting dynamics of the gun debate as the GOP fights to maintain its grip on Congress.

The NRA has put $11 million into midterm races this year — less than half what it spent four years ago in a campaign that gave Republicans full control of Congress. This year's totals are also far below the $54 million the group spent in 2016 on both the presidential and congressional races.

The shift comes as spending to su...