Outgoing North Carolina Gov. Pat McCrory has signed a measure limiting the powers of his soon-to-be Democratic successor, Roy Cooper, a move critics are calling an unprecedented power grab orchestrated by the state’s Republican-controlled legislature.

The bill McCrory signed on Friday merges the State Board of Elections and State Ethics Commission into one entity comprised equally of Democrats and Republicans. Previous state law would have allowed Cooper to put a majority of Democrats on the board, which sets the rules for the state’s notoriously burdensome balloting.

The measure also makes elections for appellate court judgeships partisan by requiring candidates to be listed on the ballot alongside their political party.

Cooper said Friday he will challenge the move and has threatened to sue the legislature.

"Once more, the courts will have to clean up the mess the legislature made, but it won't stop us from moving North Carolina forward," Cooper said in a statement.

Protesters packed the halls of the General Assembly Friday as lawmakers voted on another bill that would require Senate confirmation for cabinet appointments. The state Senate voted to approve that measure Friday afternoon, sending it back to the state House for final consideration.

At least 16 people were arrested Friday, according to General Assembly police.

"They’ve decided now to go back and frustrate the will of the voters," Rep. Larry Hall, a Democrat, said of the legislature's action.

The series of measures were introduced in a surprise move Wednesday during a special session ostensibly called by the General Assembly to consider relief for Hurricane Matthew victims. Lawmakers did indeed approve a $201 million aid package earlier in the day, but then moved onto the legislation aimed at curbing the power of Cooper, who beat Republican McCrory last month by about 10,000 votes.

McCrory did not concede until last week -- a full month after voters cast their ballots -- following numerous failed attempts to lodge complaints about the election results. No evidence of widespread voting fraud ever came to light.

In his first national television interview since winning the gubernatorial contest, Cooper told MSNBC's Chuck Todd Thursday that the legislature's action was a "partisan power grab that goes far beyond political power."

"What they are trying to do with these process changes is to limit my ability to want to raise teacher pay, to expand Medicaid," Cooper said. "This is why people are mad, and this is why people don't like government because of these kind of shenanigans."

On Friday, Cooper left open the possibility of taking legal action.

Once more, the courts will have to clean up the mess the legislature made, but it won't stop us from moving North Carolina forward. — Roy Cooper (@RoyCooperNC) December 16, 2016

It’s not the first time North Carolina’s legislature has used a special session to ram through controversial legislation with little to no warning or discussion. Last March, McCrory hastily signed a measure restricting bathroom access for transgender individuals that lawmakers similarly approved in one-day special session, sparking a national backlash.That legislation, HB2, led to boycotts from businesses, musicians and sports leagues.