CINCINNATI — An appellate Court panel rejected a motion by Michigan’s Secretary of State to restore the ban on straight party voting after a U.S. District Court judge in Detroit ruled it unconstitutional.

In December, the Republican-controlled legislature passed the measure, which would have barred voters from choosing all the candidates of a political party by checking its box on the top of the ballot. People would have to vote for each race individually.

But rights group sued the state, saying that the ban violates the Voting Rights Act and the Equal Protection Clause of the 14th Amendment.

In June, Judge Gershwin A. Drain found that banning straight-party tickets would largely affect African American communities, increasing the time it would take to vote.

“Generally, as the African American population increases in a county, so does the use of straight-party voting,” Drain wrote.

The state appealed the decision, against the recommendations of the Michigan Association of Municipal Clerks.

But an appellate panel sided with Drain.

“In the face of this burden, the state has offered only vague and largely unsupported justifications of fostering voter knowledge and engagement,” appeals court Judges Karen Moore, Ronald Lee Gilman and Jane Branstetter Stranch wrote in their ruling.

Proponents of straight-party voting say eliminating it increases the time individual voters spend at the polls, which causes longer lines and makes voting more difficult.

Opponents say banning straight tickets encourages the electorate to look at each candidate’s stand on the issues.

A Fox 2 Detroit/Mitchell Poll showed this week that Democratic nominee Hillary Clinton is 10 percentage points ahead of Republican opponent Donald Trump.

With Trump on top of the ticket, straight-party voting could spell troubles for the Michigan GOP in local races.

Straight-party voting is no longer offered in 40 states.

Michigan Attorney General Bill Schuette said Michigan is not doing anything different.

The ballot for the November elections must be finalized in three weeks, but the attorney general vowed to re-appeal straight-party voting.

“We will continue to defend the laws of the State of Michigan and plan to file an emergency appeal to the Sixth Circuit for an en banc review by the full court,” he said.