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:
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.
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.
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.
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.