Now that a majority of the state's lawmakers have given their OK to a U.S. House map that splits booming, Democratic-tilted Nashville and its Black voters three ways, it is up to Tennessee Gov. Bill Lee to determine whether he will sign off on the new congressional lines.

NASHVILLE — Republican lawmakers in Tennessee on Monday completed their rapid passage of a new U.S. House map that splits booming, Democratic-tilted Nashville and its Black voters three ways, leaving it up to the governor to sign off on the new congressional lines.

The state House passed the plan after the Senate approved it late last week, making quick work of passing the once-a-decade new legislative and congressional districts. But the map is almost certain to also spur swift lawsuits by its opponents.

While the process has taken months, the proposed maps weren’t released to the public until Jan. 12, and Republican leaders who enjoy supermajorities in the House and Senate have put them on a fast-track ever since.

Republican Gov. Bill Lee has said he sees “no reason that I wouldn’t be signing” off on the new map, despite objections from Democrats and voting rights groups that the rewrite would unfairly dilute the influence of Black voters in Nashville. On Monday, Lee added that he hadn’t looked specifically at the new congressional layout but he would “make decisions about that map when it gets closer to my desk.”

Currently, Tennessee’s U.S. House delegation consists of seven Republicans and just two Democrats, whose districts center on Nashville and Memphis.

Democrats and community activists have long pleaded to keep Nashville’s seat whole, arguing that the Davidson County seat has largely remained intact for 200 years. It’s a district that extends into two additional counties and has about a 24 percent Black population.

The Nashville split likely makes any Democrat, including longtime Nashville U.S. Rep. Jim Cooper, a significant underdog to retain his seat against a Republican.

“We do not want to disenfranchise people with their vote because they think it doesn’t count and the way this map is drawn it does that,” said Rep. Vincent Dixie, a Black Democrat from Nashville.

Republicans have expressed confidence that the map will withstand a court challenge. They contend having three congressional members would benefit the city, without directly addressing that their representatives would likely all be Republicans, despite the city’s preference for electing Democrats. They have also deflected answering directly how much racial makeup influenced the map-making decisions, pointing to their confidence that the proposal complies with the Voting Rights Act.

The new district where Cooper lives — jagging through slivers of southern and eastern Nashville as it branches in multiple directions into five other counties — would include about 11.8% Black residents out of those old enough to vote. The other two would be 8.6 percent and 15.5 percent Black.

Rep. Harold Love Jr., a Black Democrat from Nashville, said Black voters in Davidson County have previously been able to collectively influence what issues their congressional representative focuses on while in office. Splitting up Davidson County, Love warned, could significantly diminish that impact while competing with white, rural voters.

The state Democratic Party has promised to sue over the map, and others may join them. But the legal path for getting the new Republican-authored U.S. House map altered faces significant obstacles.

Outside of the bill sponsor, no Republicans defended the map during Monday’s debate.

In 2019, the U.S. Supreme Court ruled that partisan gerrymandering of congressional and legislative districts is none of its business.

Courts have, however, barred redistricting aimed at reducing the political representation of racial minorities for a half-century. Protections exist under the U.S. Constitution and the Voting Rights Act, which the U.S. Department of Justice has used to sue Texas over its state and congressional maps. Both have varying degrees of proof required in the courts.

Another complicating factor — Tennessee lacks the kind of state requirements that advocates in Ohio, for one, have used in recent redistricting challenge wins. Ohio’s Supreme Court declared invalid GOP-spearheaded state legislative and congressional maps in recent decisions. Those were based on 2015 and 2018 constitutional amendments that require an attempt at avoiding partisan favoritism.

Nationally, Republicans need a net gain of five seats to flip U.S. House control.

While both parties have gerrymandered, these days Republicans have more opportunities. The GOP controls the line-drawing process in states representing 187 House seats compared with 75 for Democrats. The rest of the states use either independent commissions, have split government control or only one congressional seat.

For Democrats, the worst case scenario of losing well over a dozen seats in the U.S. House appears unlikely to happen. After some aggressive map drawing of their own in states with Democratic legislatures, some Democrats predict the typical congressional district will shift from leaning to the right of the national vote to matching it, ending a distortion that gave the GOP a built-in advantage over the past five House elections.

(This AP story is by Jonathan Mattise and Kimberlee Kruesi.)