Abortion most certainly is not the most important issue. But why should the GOP accept a candidate who is left of the base on this issue when they could get a candidate who shares Rice's strengths on defense issues but who is also pro-life? The Dems certainly arent' going to accept anything less than a hard-line pro-choicer.
Now, if a Rice or Giuliani could convince the base that they would at a minimum not use the office of President to advance the pro-choice cause, and that they would nominate conservative judges, then their candidacy would be more attractive. But really, if a Reagan and Bush wind up picking just two reliably good Sup Court justices between them, then what chance is there that a Rice or Giuliani could be counted on?
It's really up to the senate on who gets on the supreme court. Jesus himself could be president and he would meet a democrat filibuster. Frist is afraid of the "nuclear option".
That's because Democrats are not the party whose mantra is: "I'm personally opposed, but ..."
It's only the Republicans who feel the need to compromise the objective truths they allegedly hold dear.