Senate Democrats defeated a GOP attempt Wednesday to “hijack” the veterans’ educational benefits bill, but the failed vote may be enough to shield Sen. John McCain (R-Ariz.) from attacks along the campaign trail.

By a 55-42 vote, the Senate blocked the amendment authored by Sen. Lindsey Graham (R-S.C.), who tried to attach it to an unrelated bill giving public safety workers the right to unionize. Seven Republicans joined a united Democratic Conference in voting down the amendment, and the three presidential candidates were absent.

“Sen. McCain is looking for political cover here in a very difficult situation, and so what he’s done is try to hijack another bill,” said Senate Majority Whip Dick Durbin (D-Ill.), an Obama supporter. “He’s trying to bring his version of the GI bill to a vote on the Senate floor, so he can say he at least tried.”

Wednesday’s action shows how the two sides are increasingly using the Senate floor to pivot ahead of the general election. Minority Leader Mitch McConnell (R-Ky.) forced Wednesday’s consideration of the Graham amendment by filing a motion to end debate on the plan. That follows a successful effort by McConnell to force a vote this week on a Republican energy bill to highlight the differences between the two parties on reducing gas prices.

Without McConnell’s move, Republicans would not have had the chance to vote for the Graham measure but could have been forced to vote up or down on the larger Iraq funding package that includes Webb’s bill. And if Democrats agreed to remove Webb’s measure from the supplemental bill and vote on it separately, they likely would lose Republican support for the bill that could cost $200 billion.

Republicans said they expect Democrats will block their amendments to the emergency-spending bill, and they also said forcing the vote on McCain’s bill proves they support veterans.

“The idea that you’re going to have Republicans vote against a GI bill in a war supplemental and run ads that they don’t care about veterans, well that’s not going to happen,” Graham said.

Graham’s plan would give $2,000 in monthly benefits to veterans who have served 12 years or longer.

The Webb plan, modeled after the GI Bill from World War II, would ensure that veterans receive educational benefits for 36 months, including the full cost of tuition plus books and a monthly stipend. Some Republicans object to the cost and scope of the measure. McCain and Graham say it would hurt military retention.

The Webb legislation is expected to be added to the supplemental bill in the House and Senate. The Senate Appropriations Committee plans to mark up its own supplemental bill Thursday.

Webb said the GOP move was an “irresponsible act” and done in “bad faith” after he and Graham had started to discuss ways to reach a compromise.

But Graham said that he warned Webb Tuesday that he would be forced into that action since it was the “last vehicle” to attach the plan to.

Majority Leader Harry Reid (D-Nev.) said the vote is a “message to Bush-McCain Republicans that the U.S. Senate will not stand for political games at the expense of our nation’s first responders and veterans.”

Don Stewart, a McConnell spokesman, said that by criticizing Republicans for forcing a vote and unilaterally adding the provision in the supplemental bill, Democrats were taking hypocritical positions.

“It’s a curious position to take,” he said.