Here is why the Republicans intervened, from today's Boston Globe:

"A one-page memo, distributed to Republican senators by party leaders, called the debate over Schiavo legislation ''a great political issue" that would appeal to the party's base, or core, supporters.

The memo singled out Senator Bill Nelson, Democrat of Florida, who is up for reelection next year and is potentially vulnerable in a state President Bush won last year.

''This is an important moral issue and the pro-life base will be excited that the Senate is debating this important issue," said the memo, which was reported by ABC News and later given to The Washington Post. ''This is a great political issue because Senator Nelson of Florida has already refused to become a cosponsor and this is a tough issue for Democrats."