Voters rendered a split decision on gun control measures in the election, approving universal background checks for private firearms sales in Nevada while narrowly rejecting them in Maine.

Gun safety advocates had poured millions of dollars into backing the initiatives in an effort to combat the political might of the gun lobby’s National Rifle Association.

The measure was defeated in Maine by 51.0 percent of votes to 48.9 percent, or about 12,700 ballots, the Bangor Daily News reported. Nevada voters approved a similar proposal by 50.5 percent to 49.6 percent, state election officials said.

Both ballot initiatives were backed by Everytown for Gun Safety, the gun control group founded by billionaire former Mayor Michael Bloomberg, and polls had suggested the measures would pass.

The votes were seen as a crucial test of the gun safety campaign’s decision to adopt a state-by-state strategy after efforts to pass legislation failed in Congress.

Gun control supporters won victories in two other states. Washington state voters easily approved a measure giving judges the power to keep dangerous individuals, such as accused domestic abusers, from possessing guns. In California, residents backed a referendum that bans large-capacity ammunition magazines and requires some people to undergo background checks in order to buy ammunition.