House conservatives head to Philadelphia today for the annual Heritage Foundation Conservative Members Retreat as their movement faces a critical test of its ability to shape the Republican Party agenda.

It also comes at a delicate time for House Republicans, who pledged that their Conference members were unified coming out of their own retreat last weekend but still bear the scars of last year’s intraparty battles over the debt ceiling and government spending.

“I am much more confident this year that you’re not going to be in a reactive mode the way you were last year,” House Majority Leader Eric Cantor said at the House GOP retreat in Baltimore.

The Virginia Republican also predicted there would be no government shutdown fights this year, a nod to the fact that a large part of 2011 was consumed with such battles, distracting from other parts of the new majority’s agenda.

“We’re not going to have one this year. We’re not going to have a government shutdown,” he said at the retreat. “Thirty days out [from the election] … people don’t want to see a shutdown.”

This week’s Heritage retreat also comes as conservatives in Congress and across the country are at something of a crossroads. After riding the tea party wave into power in 2010, conservatives in the House have seen the once powerful movement ebb a bit and its influence wane in electoral and legislative affairs.

Despite their strong showing in 2010, conservatives have increasingly found themselves at odds with House leaders. Heritage’s political wing, Heritage Action for America, became embroiled in an ugly dust-up between Speaker John Boehner’s (Ohio) leadership team and the Republican Study Committee during this summer’s debt ceiling debate, and the group’s decision to urge opposition to a number of bills supported by leadership has further strained relations.

Although the retreat is not officially associated with the conservative Republican Study Committee, Chairman Jim Jordan (Ohio) and other RSC members are expected to participate.

The conservative charge in 2010 did help fundamentally reshape the appropriations process in 2011 — turning it from a discussion of how to spend money to how best to cut federal spending.

But their natural enemies, appropriators, came out of the previous year more powerful than they entered it because legislative gridlock meant spending measures were some of the few legislative items to pass.

More broadly, little of the conservative legislative agenda beyond the issue of spending has seen much action. The House has passed a host of regulatory reform bills and repeated repeals of President Barack Obama’s health care law, but they have all died in the Senate.

Conservatives have also seen much of their rhetoric co-opted not only by moderate and mainstream Republicans but even by Democrats, such as Minority Leader Nancy Pelosi (Calif.), who now at least give a nod to shrinking the size of government and tackling the national debt.

Even the Obama administration has gotten on the small-government bandwagon, putting forth proposals to eliminate duplicative functions, most notably by restructuring the Commerce Department.

Dubbed “The Spirit of Independence,” the meeting of some 50 House conservatives focusing on broad ideological and tactical themes is a marked departure from the retreat’s traditional focus on specific policy issues facing Congress, organizers said.

“At ‘The Spirit of Independence’ we will look broadly at the progressive attack on America’s principles of liberty, opportunity and constitutional government and how conservatives reclaim those principles and our country as we move into the critical year of 2012,” Heritage Government Studies Director Dani Doane said.

For example, Thursday night will feature discussions on “Is America’s Decline Inevitable?” led by the American Spectator’s John Fund, as well as Steve Forbes. Another session will be on the “Back Bone of America,” moderated by Rep. Tom Rooney (R-Fla.). Former U.N. Ambassador John Bolton will make a presentation on international affairs.

Other sessions include “Creating Opportunity and Prosperity in the Free Markets,” “What Americans Think of the Federal Leviathan,” “The Founders’ View of Civil Society” and “Civil Society and Poverty’s Rise.”

The retreat will not, however, hold a discussion of military spending — traditionally a mainstay of the events — but will instead focus on the role of the military in shaping the nation.

Participants will also discuss the nation’s historical underpinnings, including a panel on the risks taken by the founders in drafting the Declaration of Independence.

“This retreat is a lot different” from past Heritage events, a source with the foundation said, explaining that the organizers have “seen what we believe is a real growth in the progressive agenda.”

The goal of the retreat, this source said, is to map out a conservative approach to the broad political struggles being fought this year, rather than specific legislative fights.

This year’s political and electoral landscape provides a perfect opportunity for a broader discussion, the Heritage source argued, quipping, “Let’s be honest: This isn’t a legislative year” in Congress.