TALLAHASSEE, Fla. (AP) _ Three state Supreme Court justices being targeted by Republicans and other conservatives said Friday that such partisan and special interest attacks are threatening the independence and fairness of Florida's judicial system.

The Florida Republican Party this year broke with a nonpartisan tradition in merit-retention elections by opposing the three justices who will be on the Nov. 6 ballot for up-or-down votes.

They also have drawn opposition from Americans for Prosperity, a group formed by the conservative billionaire brothers Charles and David Koch, as well as a small, grass-roots organization that also unsuccessfully campaigned against two other justices in 2010.

``Any time you have the threat of a judge making a decision because he or she is looking over her shoulder or his shoulder as to who has the check book behind you the next time around you've just defined a corrupt system,'' said Justice R. Fred Lewis.

Lewis and his two colleagues spoke at a forum on merit retention sponsored by the League of Women Voters and Florida State University's law school. The justices said if opponents are successful in turning them out of office, it would mean a return to the kind of corruption that riddled the Supreme Court in the 1970s and led to the creation of merit selection and retention in an effort to remove politics from the judicial system.

The justices are asking voters for six more years. If they are ousted, Republican Gov. Rick Scott would appoint replacements from slates recommended by the Supreme Court Judicial Nominating Commission.

Lewis and Justice Barbara Pariente were appointed by Democratic Gov. Lawton Chiles. Justice Peggy Quince was jointly appointed by Chiles and Republican Jeb Bush when he was governor-elect. All have served a two-year term as chief justice.

Florida voters have not removed anyone since the merit retention system began in the 1970s for the justices and appellate court judges. Pariente said each of the justices on this year's ballot have been retained twice before without any organized opposition, but this time is different.

``It is not about just the three of us, but it is about our system, the fair and impartial judiciary,'' Pariente said. ``We cannot have a state where judges and justices who are up for merit-retention are fearful that they will lose their jobs simply because there is some segment that has money and the ability to speak out and that wants to intimidate the third branch of government.''

Florida Democratic Party Chairman Rod Smith has alleged the GOP's opposition is ``nothing more than a partisan power grab'' by Scott.

Smith's Republican counterpart, Lenny Curry, denies Scott had anything to do with his party's decision, saying the idea came from rank-and-file Republicans.

``The charge of `injecting politics' into what is already an issue before the voters is nonsense of the highest order,'' Curry wrote in an op-ed column published in Florida newspapers. ``Judges in Florida are appointed by politicians. They decide political issues all the time.''

The party's executive board unanimously voted to oppose the justices, citing their ``judicial activism'' and singling out a 5-2 ruling in 2003 that ordered a new trial for a convicted killer on grounds his lawyer had been ineffective.

The U.S. Supreme Court set aside the ruling and restored Elton Nixon's death sentence. He was convicted of kidnapping a woman from a Tallahassee mall, tying her to trees with jumper cables and then setting her on fire.

A television ad by Americans for Prosperity focuses on another 5-2 decision that removed from the 2010 ballot a state constitutional amendment offered by the Republican-led Legislature. It would have allowed Floridians to opt out of a requirement to obtain health insurance under President Barack Obama's Affordable Care Act.

``Shouldn't our courts be above politics and protect our rights to choose?'' the ad asks.

The state, though, conceded the amendment's ballot summary was inaccurate and misleading but asked the justices to substitute the body of the proposal for the summary. The majority, including the three justices up for merit retention this year, ruled that only the Legislature had the power to rewrite the summary.

That's what lawmakers then did. The amendment is on this year's ballot, but a U.S. Supreme Court ruling upholding the federal law likely makes it a moot issue.

That's just one of several rulings that have upset Republicans, going back to the state justices' refusal to stop Florida's 2000 presidential ballot recount. Again, they were overruled by the U.S. Supreme Court, handing Republican George W. Bush a 537-vote victory that gave him the presidency over Democrat Al Gore.