Washington (CNN) - Ratcheting up the pressure on Democratic leaders to accept steep cuts in government spending, freshman Sen. Joe Manchin of West Virginia said Tuesday he would back a bill that places strict caps on spending enforced by automatic cuts if those caps were breached.
The move by the moderate Democrat, who is up for re-election in a swing state, is evidence of the acute sensitivity many Democrats have about the politically charged issue of reducing government debt. Top Senate Democrats oppose spending caps as too inflexible. Manchin's announcement could weaken Democratic leaders in their negotiations with Republicans over the coming weeks about how to cut spending and curb the nation's debt.
Most immediately, Democratic leaders are trying to get Republicans to agree to raise the government's debt ceiling - which will be hit next month - without forcing cuts Democrats consider draconian. Congressional Republicans and some Democrats have said they will not vote to raise the borrowing limit unless it is tied to reforms in government spending.
In his remarks in West Virginia, Manchin said his support for the spending caps measure and, separately, for a balanced budget amendment to the Constitution, "would offer a good framework for a bipartisan" deal to raise the debt limit.
Manchin's support for the CAP Act, means supporters of the bill are one vote shy of a majority of senators supporting it, according to the office of Sen. Claire McCaskill, D-Missouri, who co-authored the bill with Sen. Bob Corker, R-Tennessee. While that is a symbolically important threshold, it is far short of the 60 votes that would be needed to pass the bill over the opposition of Democratic leaders who control the chamber.
The Senate Republican campaign committee dismissed Manchin's gesture as politically motivated and insufficient to prove he wants to curb government spending, especially in the wake of Manchin's support for President Obama's health care reform bill and economic stimulus package.
"Senator Manchin knows full well that the proposals he is endorsing today have zero chance of becoming law because they are being blocked by the same liberal Senate Democratic leaders that he voted to put in power," said a statement from Brian Walsh, a spokesman for the committee.
The CAP Act is a "fiscal straitjacket" that would force Congress to reduce spending dramatically, according to Corker. Over the next ten years, it would reduce spending to no more that 20.6 percent of gross domestic product, down from the current level of 24.7 percent.
If Congress failed to stay under the cap, the executive branch would have "to make evenly distributed, simultaneous cuts throughout the federal budget to bring spending down to the pre-determined level," according to a summary of the bill.
Only a vote by two-thirds majority of both the House and Senate could prevent the automatic cuts.