For two years, tea party lawmakers in the House have been the stubborn barbarians at the gate, strong-arming their often reluctant Republican colleagues by refusing to compromise on spending, taxes, debt or social policy.

But Paul Ryan’s ascendency to the No. 2 spot on the Republican ticket is a signal event for a movement that counts him as one of their own. If Mitt Romney wins the election in November, a tea party favorite will be a heartbeat from the Oval Office.

Ryan is now unquestionably the face of the tea party caucus in Washington, and his success is certain to embolden House lawmakers whose proudly unyielding approach to governance has contributed to legislative gridlock.

Once considered a fringe of the conservative coalition, tea party lawmakers are now indisputably at the core of the modern Republican Party.

For Romney, the decision to pick Ryan has quickly helped to validate him in the eyes of skeptical tea party members in the House.

Many in the movement had worried that a President Romney would hardly be an ally for their legislative goals.

Choosing Ryan eases those concerns even as it marks a shift in the movement’s balance of power.

Ryan, in his speech accepting the role of Romney’s running mate, touted his ability to reach across the aisle to find solutions that are workable to members of both parties.

But his success may help to harden the political impasse in Washington between Democrats and Republicans.

A huge post-election debate is looming over the fate of the Bush-era tax cuts and entitlement spending, and Ryan has been urging tea party members to stand firm.

If Republicans win the White House in the fall but fail to take the Senate, tea party members in the House may see even less reason to compromise on their drive to make the federal government smaller.

Within the tea party caucus, Ryan is not the most absolutist. He voted for the TARP bailout of big banks near the end of George W. Bush’s presidency. And he voted for the bailout of the auto industry. A six-term congressman who has worked in Washington his entire career, Ryan is an insider-type politician who works from within the system, not against it.

But as chairman of the House Budget Committee, Ryan has resisted pressure from some in his party’s leadership to compromise with President Barack Obama’s administration in the interests of a grand bargain that many tea party members see as selling out.