Speaker John Boehner (R-Ohio) was forced to rely on 81 House Democrats to push through a six-month spending measure Thursday over the objections of his right flank — a stark political reality that could hurt him in future battles.

“I think anytime we have defections it lessens the Speaker’s bargaining position because people think, ‘Oh, they can’t pass something,’” Rep. Steven LaTourette (R-Ohio) said.

Rep. John Kline (R-Minn.) agreed, saying, “Obviously you are in a stronger position if you can control the outcome in your own party.”

Boehner, House Majority Leader Eric Cantor (R-Va.) and House Majority Whip Kevin McCarthy (R-Calif.) fell well short of their goal of securing the 218 GOP votes needed to pass the bill without Democrats’ help. Boehner lost 59 Republicans in the 260-167 vote, including a number of freshmen, such as Rep. Tim Scott (S.C.), who is a member of the House Republican leadership team.

The Senate is expected to vote on the bill Thursday afternoon.

According to a Democratic aide, McCarthy called House Minority Whip Steny Hoyer (D-Md.) earlier in the day to ask for help on the vote and indicated he would need 70 to 80 votes.

Long after the 15-minute vote had officially run out of time, Boehner found himself stuck at 173 Republican and Democratic “yes” votes, with scores of Democrats still holding out. Hoyer then voted for the bill, quickly bringing along 45 Democrats and getting over the 218-vote hump. Ultimately, 81 Democrats voted in support — but Minority Leader Nancy Pelosi (Calif.) was not one of them.

To be sure, Boehner still mustered support from a majority of his Conference, as well as two key groups within it. While 27 freshmen voted against the bill, 60 others voted for it. Similarly, members of the conservative Republican Study Committee overwhelmingly voted for the bill, with more than 120 RSC members voting in favor of passage and 51 voting against.

Nevertheless, the overall level of defections was significant and deeper than many senior aides expected.

The collapse of support from within the GOP came despite the fact that Boehner had won a major victory last week in forcing Senate Democrats and the White House to accept deeper cuts than they had originally proposed.

Last week’s historic agreement marked the largest cuts in spending since World War II. And, perhaps more importantly, Boehner had forced President Barack Obama and Senate Majority Leader Harry Reid (D-Nev.) into a battle over how large spending cuts now and in the future would be.

Despite early enthusiasm from his Conference, Boehner was faced with dozens of defections from seasoned Republicans and freshmen alike by the time Thursday’s vote occurred.

According to Republicans, a number of factors contributed to the surprising lack of support. Several GOP aides conceded that standing by their pledge to publish legislation three days before a vote gave conservative activists opposed to the deal ample time to pick apart the agreement and cast it as a failure to control deficits.

Rep. Jack Kingston described the three-day rule as a “double-edged sword.”

“I think the three-day layover has gotten a lot of people able to read it out front, which is one of our goals, but you also suffer from it a little bit because you look at the reasons to vote ‘no’ and people can always find one if given enough time,” the Georgia Republican said.

A Congressional Budget Office report circulated Wednesday posed the second problem. It indicated that the agreement would have virtually no effect on this year’s deficit, and conservatives latched onto the report as proof that Boehner had negotiated a bad deal.

Those attacks clearly concerned Boehner, who, in a rare move, took to the floor Thursday before the vote to defend the agreement.

“There are some who claim the spending cuts in this bill aren’t ‘real,’ that the bill is full of ‘gimmicks.’ That’s nonsense. A cut is a cut. … Every dime of cuts in this bill is a dime that Washington will spend if we leave it on the table. And if you vote ‘no’ on this bill, you’re voting to do exactly that,” the Ohio Republican said.

In fact, in a show of just how important the agreement is, Boehner cast just his second vote of the year Thursday. He previously voted in favor of a bill that would repeal Obama’s health care overhaul law.

“The Speaker knows some Members are going to take heat for this vote,” Boehner spokesman Michael Steel said Thursday after the vote. “He wanted to be clear that he’s right there with them.”

In the weeks before Boehner cut the deal, members of his leadership team had become increasingly wary of how the negotiations with Democrats were going, arguing it would be difficult to muster enough Republican votes unless deeper cuts were made.

Still, several House Republicans backed Boehner’s decision to move forward on the package despite having to look to House Democrats to pass the bill.

“He’s said repeatedly the House needs to work its will, so we’ve gone back to having open rules and structured open rules where we get lots and lots of amendments, votes,” Kline said.