House Democrats launched a surprise procedural offensive on a budget plan Friday in an effort to put conservative Republicans on the spot – and fell just nine votes of succeeding.

The rare move came during a vote on a fiscal year 2012 budget proposal by the Republican Study Committee, a group of 176 conservative House Republicans, or 76 percent of the entire Republican conference.

The RSC proposal was one of four alternative budgets being considered on the House floor Friday, none of which was expected to pass. The House Republican leadership budget, proposed by Rep. Paul Ryan (R-Wis.), was expected to easily pass later in the afternoon.

RSC chairman Jim Jordan’s (R-Ohio) spending plan would make more drastic cuts than the Ryan plan would, balancing the federal budget by 2020 and enacting $9.5 trillion in cuts over the next decade. Ryan’s plan would bring the budget into balance by 2030 and make $6.2 trillion in cuts.

If House Republicans had been forced to pass the much deeper cuts, it could have had a harmed some reelection campaigns.

When the RSC budget plan came to the House floor Friday morning, the aye votes from the Republicans were ahead of their party colleagues’ no’s. As the vote proceeded, it became apparent that most Democrats were holding their ballots.

As the deadline for the vote neared, more than 120 Democrats voted “present” on the RSC budget, while about 40 voted no. A “present” vote is not counted in the tally. That shifted the vote tally so that more members were now voting against the RSC budget than voting for it, although the margin was slim.

The Democratic move meant that if the budget plan received a majority of the votes, excluding the “present” votes, it would pass – and, since it was technically introduced as a substitute to the Ryan plan, would completely wipe out that plan.

As the Democrats who had voted no began changing to “present,” the margin narrowed even more. In the end, the RSC budget failed on a 119-to-136 vote, with 172 voting “present.” Sixteen Democrats voted no.

That means that if just nine more Republicans had backed the RSC proposal, it would have passed.

The RSC traditionally proposes its own budget every year, as do other House caucuses, including the Congressional Progressive Caucus and the Congressional Black Caucus.

During the debate over funding the government for the 2011 fiscal year, the RSC proposed an amendment that would have cut an additional $22 billion from federal agencies – such a sharp decrease that even some RSC members opposed it. The amendment failed on a 147-to-281 vote, although more Republicans backed the amendment than opposed it. If Democrats had employed their legislative move back then, the amendment would have passed.

In a statement explaining the strategy behind the vote, the office of House Minority Whip Steny Hoyer (D-Md.), the vote-counter for House Democrats, said Friday that Democrats were voting present “to highlight Republican divisions.”

“This vote will show which budget Republicans support,” the statement said, “the Republican budget that ends Medicare as we know it and cuts investments while giving tax breaks to the wealthiest, or the extreme RSC budget that is the GOP budget on steroids: ending Medicare as we know it and going even further in decimating investments in our future.”

That reasoning meant that “with Democrats voting present, Republicans are solely responsible for passage or failure of the RSC budget.”