Some past donors and volunteers of Indiana Democratic Senator Evan Bayh say they will pull their support for the senator if he doesn't support a health care reform bill that contains the so-called "public option."

This week, Bayh has stated that he would have trouble voting for a bill that he believes would drive up the national deficit, and possibly increase premiums on families who already have insurance. "If this is going to increase the amount that people who currently have insurance pay, I would have a very hard time supporting something like that," Bayh said.

The senator also says he has asked the Congressional Budget Office to conduct a study on how the current legislation would affect premiums for people who already have insurance.

Organizers with Moveon.org say they have about 250 signatures on a letter telling Senator Bayh they will pull their support for his re-election bid if he sides with Republicans in blocking an up-or-down vote on the bill now being debated in the Senate.

Demonstrators were planning to deliver that message today at Noon at Bayh's offices in Indianapolis and South Bend.