TALLAHASSEE — Florida voters are being asked to approve a little-noticed amendment to the state Constitution that would rewrite the way judges are appointed to the state's highest courts and strengthen the powers of governors who are leaving office.

Proponents say it is needed to avert a constitutional crisis, but opponents say it is a manufactured problem and a partisan power grab that could have ominous consequences.

Amendment 3 is the brainchild of Florida Republicans in the Legislature who describe it as a modest change needed to correct a constitutional ambiguity that could arise in 2019.

Under current law, the governor is not allowed to make an appointment to the Florida Supreme Court or the state courts of appeal unless there is a vacancy. On the same day the governor takes office in 2019 — after the 2018 elections — three of the state's seven Supreme Court justices are scheduled to retire because they will have reached the mandatory retirement age of 70. The justices, R. Fred Lewis, Barbara Pariente and Peggy Quince, are considered the court's liberal wing.

State Sen. Tom Lee, R-Brandon, sponsored the amendment as chairman of the Senate Judiciary Committee. He said his legal scholars concluded that the current law is unclear about which governor can make the appointment and a potential legal battle could set off a "constitutional crisis."

"Even if the appointments could be made on the incoming governor's inauguration day in 2019, the Supreme Court would likely not be fully functional for weeks,'' Lee wrote in an opinion piece distributed to several newspapers.

The amendment has the support of the Florida Chamber of Commerce and the Florida Council of 100 and is opposed by the League of Women Voters. It needs the approval of 60 percent of voters to become law and, recent polls show, most voters remain undecided about it.

Under the proposal, the Constitution would establish a new legal term -— "prospective vacancy" — and allow a sitting governor to fill an opening to the Supreme Court and to the courts of appeals before it occurs.

Opponents, led by a bipartisan group of lawyers including former Supreme Court Justice Harry Lee Anstead, say the amendment is a solution without a problem and the proposed language is an overreach.

"There is no impending crisis because there is no ambiguity,'' said Anstead, who served on the court from 1994 to 2009 and was appointed by Lawton Chiles. "Who would want to inject into our Constitution this dangerous term 'prospective vacancy?' "

He warned that if the legal term is applied to the courts, there might be no stopping anyone from arguing that the governor could apply the same power to people leaving other constitutional offices.

Alex Villalobos, a former Miami state senator and a Republican lawyer, has joined Anstead in working to oppose the amendment. They cite a 2006 opinion of the Florida Supreme Court, which clarified that a vacancy occurs on the day the term expires. It does not specifically address which governor has the power to fill that vacancy.

They also point to a court rule that allows the chief justice of the Supreme Court to temporarily extend the terms of the sitting justices until the governor makes appointments. In the past, the court has extended the terms of retiring justices to finish out the cases they have already heard, and it could do that again.

Anstead, for instance, stayed on the court for a month after he retired to complete his pending cases. Justice Ben Overton stayed on the court for nearly a year after he retired in 1978 — not to hear new cases but to complete old ones, said Craig Waters, communications director for the Florida Supreme Court.

"That has been a routine practice the 28 years I've been here,'' Waters said. "It doesn't make sense to bring in a new justice to learn everything a justice already learned. That's a waste of taxpayer's money."

Florida has resolved conflicts over judicial appointments before. In 1998, when Chiles was leaving the governor's office and Jeb Bush was arriving, the two men agreed to appoint Quince to the Supreme Court from the nominees provided by the Judicial Nominating Commission.

Anstead and other opponents say that the amendment, which passed on a party-line vote in both the House and Senate, is part of a decade-long attempt by the Republican Party to control the judiciary. If Gov. Rick Scott is elected and the amendment passes, the Republican governor could stack the court before he leaves office at the end of a second term. But if Charlie Crist wins election, he could do the same.

"All I'm saying is, let's get some clarification now before we know which governor would benefit,'' Lee said.

Contact Mary Ellen Klas at meklas@MiamiHerald.com. Follow @MaryEllenKlas.