Missouri on Wednesday joined a growing list of states allowing most adults to carry concealed weapons without a permit, as the state's Republican-led Legislature used its supermajority to loosen existing gun laws.

The measure, described by supporters as "constitutional carry," allows people to carry hidden guns anywhere they can currently carry weapons openly, effective January 1. Missouri will join 10 other states with laws that allow most people to carry concealed guns even if they haven't gone through the training required for permits, according to the National Rifle Association, which supported the legislation.

The legislation also would create a "stand-your-ground" right, meaning people don't have a duty to retreat from danger any place they are legally entitled to be present. The NRA says 30 states have laws or court precedents stating people have no duty to retreat from a threat anywhere they are lawfully present. But Missouri's measure makes it the first new "stand-your-ground" state since 2011.

It also expands the "castle doctrine" by allowing invited guests such as baby sitters to use deadly force if confronted in homes.

The guns legislation prompted some of the most intense debate Wednesday. Democrats asserted it could put racial minorities at a greater risk of being fatally shot.

"The targets in our area are black boys, not pheasants," said Sen. Maria Chappelle-Nadal, who represents Ferguson, where sometimes violent protests broke out after the fatal police shooting of 18-year-old Michael Brown in 2014. The police officer, Darren Wilson, was cleared of wrongdoing by state and federal investigations.

"What I don't want to get to is the point where there is a trigger-happy police officer or bad Samaritan like Zimmerman who says, 'Black boy in the hood. Skittles. Let's shoot,"' Chappelle-Nadal said, a reference to Trayvon Martin, a black 17-year-old who was walking back from a Florida convenience store after buying ice tea and Skittles when he was fatally shot by neighborhood watch volunteer George Zimmerman in 2012.

Republican said such fears of greater gun violence are misguided. "The basis of this whole bill is that it allows law-abiding citizens to protect themselves and their families," Republican sponsor Sen. Brian Munzlinger said.

State lawmakers also moved to potentially tighten voting requirements. The elections law change would require people to show a government-issued photo ID at the polls starting in 2017, if voters also approve a proposed constitutional amendment on the November ballot.

Lawmakers overrode 13 vetoes Wednesday while adding to Democratic Gov. Jay Nixon's record as the most overridden governor in Missouri history, a distinction made possible by an era of extreme political division in the Capitol. Heading into Wednesday, lawmakers had successfully overridden Nixon on 83 bills and budget expenditures over his two terms in office -- nearly four times more overrides than the combined total for all other governors dating back to 1820 when Missouri was still a territory.

The votes occurred as many lawmakers are campaigning for re-election in November. "I think a lot of the things that we've done today will resonate in the election in a very positive way," House Speaker Todd Richardson said.

The Associated Press contributed to this report.