Amid all the recriminations about the electoral ineffectiveness of some Tea Party–backed candidates, it’s easy to lose sight of a central fact: It’s doubtful that, without a newly emboldened grassroots movement, Republican politicians would have been able to create enough momentum against Obama to produce the landslide of November 2.

As ebullient progressives descended on Washington for Obama’s inauguration in January 2009, many Republicans assumed the fetal position. Party strategists wondered just how much they could openly oppose the new president’s agenda, lest they be tarred as obstructionist or even racist. Barely a month into Obama’s term, his political operation tied Republicans in knots by pressuring them to disown Rush Limbaugh’s “I want Obama to fail” monologue.

The very month after the inauguration, two events turned the tide, eventually leading all the way to the Republican tsunami this November.

The first was the unanimous House-Republican vote against the stimulus, which in many observers’ eyes was the moment Republicans woke up from their post-election stupor and resolved to be a real opposition worthy of grassroots support, reminiscent of the kind Bill Clinton faced leading up to his midterm drubbing. The second happened in Chicago on February 19. That morning, CNBC’s Rick Santelli, flanked by cheering capitalists on the floor of the Chicago Mercantile Exchange, tore into the administration’s mortgage-bailout plan and issued a nationally televised and YouTubed call for a Chicago tea party in July.

Empowered by the hyperconnectivity of the Web, newly energized conservative activists moved up the schedule by a few months. The first Chicago tea party happened within days, and tea parties quickly became a national phenomenon; more than a million people are estimated to have attended them on April 15, 2009 — Tax Day.

Republicans at high levels briefly fretted about the image of the GOP these unruly activists would present. Yet Republican candidates flocked to speak at the rallies, and an alliance between party and movement quickly formed, even as the movement worked to take out establishment stalwarts in primaries. According to a post-election report in the Wall Street Journal, it was the Tea Party–fueled showing at the August 2009 health-care town halls that spurred a new wave of Republican candidate recruitment — until then the missing piece to any hope of a GOP comeback.

With the mission of taking over the House accomplished, the movement is now at a crossroads, and where it goes next is a matter of crucial importance for the Right.

One option is closer cooperation with (and what cynics might call co-option by) the Republican-party structure. Given that Karl Rove’s “72-hour turnout plan” (an RNC-run effort to canvass neighborhoods and call voters that was first deployed on a massive scale in 2004) essentially did not take place this election cycle, the movement’s organizational muscle (not to mention the hearts and minds of its activist base) will be especially important to the party. It’s unclear who would be the majority shareholder if the Republican party and the Tea Party merged.

Yet deeper integration is unlikely to outlive this political moment. Just as the grassroots organization built during President Bush’s winning 2000 and 2004 campaigns did not outlive his presidency (or even, in fact, persist much beyond those campaigns), President Obama struggled mightily to conjure up the enthusiasm of his 2008 bid in this year’s listless campaign, limiting his stops to inner cities and liberal college towns. After the 2008 election, the vaunted “Obama movement” mostly fizzled out: It was moved in-house to the Democratic National Committee and given the moniker “Organizing for America.” Campaign-related activity on “MyBO,” OFA’s Web-based organizing hub, was down as much as 90 percent from 2008 as activists recoiled at the shift from the frenetic energy of a campaign to White House command and control. The experience should provide a cautionary tale to the Tea Partiers, with their more humble origins: Hitch yourself to established power institutions at your own peril.