Frustrated by Senate Republicans’ success in blocking Democratic legislative priorities, Democrats may seek to employ the budget process to advance Medicare legislation this year.

Using a budget procedure called “reconciliation” to make changes to Medicare would allow such legislation to pass the Senate by a simple majority vote, precluding a GOP filibuster. But the tactic would anger Republicans who otherwise might be inclined to cooperate, and President Bush would almost certainly veto any Medicare bill produced without GOP input.

The key decision will be made by Democratic conferees on the fiscal 2009 budget resolution soon after Congress returns from its spring break March 31.

The House version of the fiscal 2009 budget resolution calls for Medicare reconciliation legislation. The Senate version does not, but Democratic conferees could decide to keep the instructions for reconciliation in the final version.

While the issue is far from decided, the potential reconciliation strategy has so alarmed Sen. Charles E. Grassley of Iowa, the senior Republican on the Finance Committee, that he delivered a floor speech criticizing the idea March 11, after meeting with senior Bush administration officials to discuss Medicare.

“If the Democratic leadership insists on using budget reconciliation for the Medicare bill, they will fail to get a bill enacted,” Grassley warned.

The immediate driver for Medicare changes this year is the need to halt a 10.6 percent cut in Medicare payments to doctors that is scheduled to take effect July 1. But Grassley fears Democrats might try to go further, making major changes to the program and to a separate children’s health insurance program.

“The president won’t sign a bill that lacks involvement and support by Republicans,” Grassley said. “Since reconciliation cuts Republicans out of the process, it won’t work.”