No, the people of Pennsylvania in both the primary and the general election voted for the guy. They are responsible.
There are ways to make RINOs toe the line, and they don't depend entirely on the Republican leadership in the Senate. How many bills has Bush vetoed? How often has he disciplined dissenting RINOs by taking away their pork? How often has he punished his enemies when they got out of line? No wonder he can't control the party.
The RINO's as a block can stop anything that they want. They have that power. It is the people who elected them that gave them that power.
Historically, Republicans have controlled their RINOs by insisting that they vote with the party on critical bills or other votes. The rest of the time there is a tacit understanding that they can vote against, because their votes are not needed.
This is one of those votes where at least some of the RINO votes are needed. There's something badly wrong with the leadership and with party discipline if they can't call in those chips.
Part of the problem lies with Frist and his predecessor, no doubt; but part of the problem also lies with Bush as the de facto head of the party.