With a few new leaders emerging -- and more than a few old leaders not going away -- Republicans have witnessed battles pitting congressional leadership against White House aspirants, voices of the past against possible voices of the future, and talking heads vs. decision-makers.
Here are 11 key moments from the first 100 days of Republicans as opposition party against the White House:
No. 1: United Vote
It was only Day 9 of the Obama presidency, but it would mark the defining moment for the Republican opposition of the first 100 days.
Every single Republican in the House voted against the $789 billion economic stimulus plan, despite an intense lobbying push by the Obama White House to achieve a bipartisan victory on his first major legislative priority.
The remarkable display of unity was a significant victory for House Republican Whip Eric Cantor, R-Va. -- one of the party's new young faces.
It was also an embarrassment to a president who seemed to try everything -- including rides on Air Force One and a White House Super Bowl party -- to get the support of at a least a few moderate Republicans.
The vote also served as a stark reminder of Republican powerlessness: Even when totally united, they could do nothing to stop, or even significantly influence, the Obama agenda.
No. 2: Limbaugh's Lips
Rush Limbaugh knew exactly what he was doing when he declared, "I hope Obama fails."
The problems came when Republican leaders were asked whether they agreed. It put GOP elected officials in a bind: Either contradict perhaps the most powerful force in the conservative media, or be accused of rooting against the president of the United States.
El Rushbo's comments fed directly into Democratic lampooning of Republicans as the "party of no." And with the few Republicans who contradicted Limbaugh rushing to apologize for it, the leadership vacuum in the GOP was exposed -- a vacuum that Limbaugh and others have been only too happy to fill.
No. 3: Tea Time
Technically, the massive anti-tax, anti-spending Tax Day protests had nothing to do with the Republican Party.
But the grassroots fervor behind by the "tea party" protests showed the potential of conservative online organizing, with anger at President Obama and Democrats in Congress bubbling over at sites nationwide.
It's not yet clear whether the outrage can be channeled in something more than protests, or even whether the turnout can be replicated. And it's a force that Republicans are eyeing warily, with its anti-incumbent tones potentially dangerous to members of both parties.
Still, for a party that would love to have an answer to the left's MoveOn.org, the protests were heartening.
No. 4: Pelosi's Proclamation
Just three days into the new presidency, a Democrat did more for Republican unity than any GOP leader.
With Capitol Hill consumed by the president's call for a massive stimulus bill, House Speaker Nancy Pelosi, D-Calif., announced that House Democrats had gone forward and crafted a measure without Republican input.
"Yes, we wrote the bill," Pelosi declared. "Yes, we won the election."
With those words, the seeds of Republican opposition were planted.
Top GOP Moments of Obama's First 100 Days
No. 5: Gregg's Retreat
It was billed as a huge coup for Obama: Sen. Judd Gregg, a veteran New Hampshire Republican and a fiscally conservative stalwart, was set to join the Cabinet as commerce secretary.
But that plan was shattered 10 days later, when Gregg abruptly announced he no longer wanted the job.
The episode cast a harsh spotlight on the new White House's vetting process for appointments -- and sent a clear signal that opposition, not accommodation, would define the GOP attitude toward Obama in Congress.
As ranking Republican on the Senate Budget Committee, the retiring Sen. Gregg has emerged as a forceful critic of the president's spending proposals -- and one with added credibility, as a Republican who Obama wanted in his Cabinet.
No. 6: The No-Number Budget
The GOP opposition's biggest public-relations flub came on Day 66 of the Obama presidency.
Eager to disprove the "party of no" storyline, House Republican leaders announced a press conference to unveil their own budget proposal.
Responding to Obama's criticism that the Republicans had failed to offer an alternative, House Minority Leader John Boehner, R-Ohio, said, "Well, it's just not true because here it is, Mr. President."
With that, Boehner released an 18-page document entitled, "The Republican Road to Recovery." The only problem: This was an alternative "budget" with no numbers.
The Republicans on the House Budget Committee would release a more complete GOP budget the following week -- but the PR damage was done.
No. 7: Cheney Rises
The release of CIA interrogation memos from the Bush administration gave Republicans an opening to knock the Obama White House off-message on national security.
The weightiest response came not from Republicans in Congress, but from former Vice President Dick Cheney, who set the tone for the opposition.
Cheney seemed eager to engage in the public debate. He denounced the release of the memos and asked the CIA to release documents proving that the interrogation program worked.
Cheney's high-profile response gave conservatives something to cheer about. Yet the attention Cheney drew also served as a reminder that there aren't many Republicans in Congress with national stature on pressing issues of national security.
No. 8: Jindal's Long Walk
Obama's first speech to a joint session of Congress gave the Republicans a perfect opportunity to highlight a rising star.
But Louisiana Gov. Bobby Jindal's nationally televised response -- he spoke from Baton Rouge in front of an oddly out-of-place spiral staircase -- was widely panned as a disaster, with devastating comparisons to "Kenneth the Page" of TV's "30 Rock."
Even Jindal's attack on wasteful Washington spending fell flat. The Louisiana governor ridiculed a federal program to monitor volcanic activity. As if on cue, Mt. Redoubt in Alaska erupted just a few weeks later, showing it may not be a bad idea to monitor volcanoes after all.
GOP's Top Moments: Stimulus, Steele and Shaping the Future
No. 9: Stimulus Stands
The united GOP opposition to the stimulus bill didn't extend to the nation's statehouses.
The billions distributed to the states sparked a divide among Republican governors -- with potential repercussions for the 2012 field.
On one side stood South Carolina's Mark Sanford, Louisiana's Bobby Jindal, Alaska's Sarah Palin and Texas' Rick Perry, who refused portions of federal stimulus dollars based on the argument that they didn't want to grow state government spending.
Other Republican governors -- including Utah's Jon Huntsman, Florida's Charlie Crist and California's Arnold Schwarzenegger -- said they'd take federal money that would help their states close gaping budget holes.
No. 10: Chairman Steele
Michael Steele's election as chairman of the Republican National Committee -- coming barely a week after Obama's inauguration -- gave the GOP its own first to rally behind: an African-American chairman to serve as one of the most prominent counterweights to an African-American president.
Yet Steele spent his first weeks as chairman in a constant PR struggle, with his quick-witted style drawing him the wrong kind of headlines, as the party infrastructure that grew robust under President Bush withered without strong RNC leadership.
Steele has grown quiet in recent weeks -- and the RNC, a potentially powerful instrument for messaging, organizing and fundraising -- still hasn't found its place in the Obama era.
No. 11: Ghosts of Campaign Past.
His days of running for president behind him, few expected Sen. John McCain, R-Ariz., to play a major role in shaping the party's future.
But he and his inner circle have stayed in the news. His 24-year-old daughter, Meghan, has emerged as something of a voice for younger Republicans, recently offering blunt advice to Karl Rove and Dick Cheney to "go away."
Steve Schmidt, who ran McCain's campaign, has been particularly outspoken about mistakes made in 2008. Plus, with the party struggling to adjust to the new reality of gay marriage's spread, Schmidt is calling for the GOP to drop its opposition to same-sex marriage altogether -- not a likely prospect, but an intriguing contribution to the political pot.
Sarah Palin hasn't exactly gone away quietly, either. Then there's McCain himself, "mavericky" as always in the Senate -- leading a small band of allies into fights that have sometimes pitted him against his own party's leadership.