Speculation about who Barack Obama will nominate to replace Supreme Court Justice David Souter has already settled on federal appeals court Judge Sonia Sotomayor as the likeliest candidate. Who is she?

Sotomayor, the Bronx-born daughter of Puerto Rican immigrants, has been floated as a potential Supreme Court pick for decades, and has already been the subject of a nomination skirmish over Republican fears that she was being groomed for a seat on the Court. Rush Limbaugh has already attacked her as a liberal activist judge. If Obama selects her, she'll come with Republican nomination-battle talking points pre-installed.

Sotomayor came from very humble beginnings in the Bronxdale Houses, a New York City housing project, but she's always been an overachiever. She's said she knew by age 10 that she would go to college and become an attorney. She methodically prepared a career that would take her first to Princeton University, then Yale Law School, then the Manhattan District Attorney's office under Robert Morgenthau, then an appointment by George H.W. Bush to federal district court in 1991, and finally the seat she currently holds on the Second Circuit Court of Appeals. "She has a very clear-cut idea of where she wants to go," Hugh Mo, a lawyer who worked with her in the DA's office, told the Daily News in 1998. "She wants to reach the highest level of the legal profession. A Supreme Court justice is not far-fetched."

That's what Republicans thought, too, when Bill Clinton named her to the appeals court in 1997, so they tried to rough her up and make any future Supreme appointments more difficult. At the time, Sotomayor was known as a moderate judge—as anyone with their eye on the Supreme Court would have to be in order to stay viable—whose highest profile case was her well-regarded handling of the 1994-95 baseball strike. But, according to the New York Times, Republicans held up the nomination and painted her as a left-wing activist judge:

Senate Republican staff aides said Trent Lott of Mississippi, the majority leader, has agreed to hold up a vote on the nomination as part of an elaborate political calculus; if she were easily confirmed to the appeals court, they said, that would put her in a position to be named to the Supreme Court. And Senate Republicans think that they would then have a difficult time opposing a Hispanic woman who had just been confirmed by the full Senate.

''Basically, we think that putting her on the appeals court puts her in the batter's box to be nominated to the Supreme Court,'' said one senior Republican staff aide who spoke on the condition of anonymity. ''If Clinton nominated her it would put several of our senators in a real difficult position.''

The Wall Street Journal and Rush Limbaugh both took up the cause, according to the Times, with the Journal attacking her record and Limbaugh declaring during her nomination hearings that she was on a "rocket ship" to the Supreme Court.

The nomination went through, but Sotomayor was angry at her treatment, telling the Daily News that Republicans had stereotyped her as a bleeding-heart liberal simply because she was a woman and a Latina: "That series of questions, I think, were symbolic of a set of expectations that some people had [that] I must be liberal.... It is stereotyping, and stereotyping is perhaps the most insidious of all problems in our society today."

Given the ready-to-serve rancor that would attend a Sotomayor appointment, it seems unlikely that Obama would go with her. Not because he's scared of Republicans—especially after the Specter defection—but because he probably wants a high-minded, enlightened confirmation process that rises above the mudfights that they've become. He won't get that, because the Republicans are crazed wounded animals lashing out without strategy or rationale. But he'll likely want someone who can be presented as the starkest contrast against the unreasonable and obstructionist right-wing revanchists. Sotomayor, whatever her merits, doesn't have that going for her—the nutjobs have had too much time to prepare for her, and will have an easier time dragging her down into the weeds.