``I'm disappointed,'' said retired banker Alex Sink, Democratic Party activist and wife of 2002 Florida gubernatorial candidate Bill McBride. ``I think she'd make a fabulous governor.''

Sink said Castor, 63, told her this week of her decision not to run. Sink said the highly negative Senate campaign between Castor and Mel Martinez last year might be part of the reason.

It has to be, Sink said.

``We're in a very bad political environment in this country in the level of discourse,'' Sink said. ``Anybody can say anything bad about you, and it doesn't matter whether it's true or not.''

Castor, who still is in the process of telling supporters about her decision, wouldn't confirm it when reached for an interview late Thursday.

She didn't deny it, however, and said the report wasn't ``timely.''

``I've had a few discussions with people to tell them I'm very close to a decision,'' she said.

``I have some issues I care very much about and where I want to spend my time,'' including a constitutional amendment referendum drive she hopes to lead on legislative redistricting.

``I think I'd like to pursue [those issues] first and foremost,'' Castor said. ``At this point, there are a lot of good candidates out there, and I think in fairness to them it would be important for me to make a decision as soon as possible.''

For Davis, who already has announced he will run, Castor's withdrawal would present an undivided home turf advantage in the Tampa Bay area, where many voters otherwise would have faced a tough decision between two of the most prominent Democratic names in the area.

Field Narrowed

It also leaves Davis as probably the best-known Democrat in the race.

In recent polls, Castor has led the field of declared and potential Democratic candidates. Lawton ``Bud'' Chiles Jr., son of the former governor, came in second and Davis third.

Chiles withdrew from the race this week because he didn't satisfy residency requirements to hold the office.

State Sen. Rod Smith, D- Gainesville, has announced he will run. Another potential candidate, state Democratic Party Chairman Scott Maddox, has said he will run if Castor doesn't.

Davis said he couldn't comment before talking to Castor about her decision.

``Betty Castor is a tremendous public servant, and I'm working closely with her on the effort to take redistricting away from the politicians and give it to citizens. I hope to continue that,'' he said.

Maddox repeated his stance that he won't run if Castor remains in the race. ``I'm a huge fan of Betty Castor. ... Before I take the next step in my decision-making process, I'm going to wait to hear directly from her that she has absolutely closed the door to running for governor.''

Castor was expected to be the front-runner in the Democratic primary because she has won two statewide races - for education commissioner in 1986 and 1990 - and just finished a U.S. Senate race, which she lost narrowly while spending more than $11 million building her name recognition statewide.

``If she is out, the race is wide open,'' said former Tampa City Council member and prominent Democrat Bob Buckhorn. ``She had the name recognition and the ability to raise the money.''

Her withdrawal helps Davis the most, he said. ``They would have been competing for a lot of the same money, a lot of the same news coverage in the same media market, and they're similar politically - both moderate and deliberative.''

Republicans also are expected to have a primary race for governor, possibly including Attorney General Charlie Crist, state Chief Financial Officer Tom Gallagher and Lt. Gov. Toni Jennings.

After her loss in the Senate race last year, Castor founded an organization called the Campaign for Florida's Future to lead a petition drive for a constitutional amendment on redistricting.

She hopes to put the amendment on the 2006 ballot. It would create a neutral commission to draw district lines for congressional and state legislative seats.

The Legislature now draws the districts, and the party that controls the Legislature can use sophisticated computer programs to design districts beneficial to incumbents and party members.

First But Not Last

Writer Doris Weatherford, a long-time Castor supporter, said she fears if Castor doesn't run for governor, it will mean the end of her career in elective politics - ``a tremendous loss to us,'' she said.

There still may be a Castor on next year's ballot.

Castor's daughter, Hillsborough County Commissioner Kathy Castor, is widely expected to run for Davis' congressional seat.

``Knowing how close the Castor family is, I wouldn't be surprised if [Betty Castor] isn't ready to pass the torch to her daughter and work just as hard as she did for herself,'' Buckhorn said.

Castor long has been one of the most prominent political faces in the Tampa Bay area and has compiled a long list of political firsts: first woman elected as a Hillsborough County commissioner, first female Florida Senate president pro tem, first woman elected to the Florida Cabinet, first female president of the University of South Florida.