Republican ranks in Congress are thick with hard-right lawmakers elected to thwart former President Barack Obama and light on nuts-and-bolts legislators, especially those experienced in working with a GOP president.
That could prove to be a formidable challenge as Republicans transition from an opposition party to a governing one.
Tea party lawmakers who are used to fighting Obama - and sometimes their own leaders - now have to pull together as a team to try to advance President Donald Trump's agenda into law, starting this week with repeal of the 2010 health care law and a possible replacement.
Conservative purity tests must get tossed out the window; instead the mandate is to figure out what can actually get enacted into law. That requires forging consensus, working within parameters set by Trump - and willingly accepting lumps and losses in intra-GOP debates and voting for what compromise eventually emerges. These are realities that some Republicans are learning more quickly than others.
"When you're in the opposition, you get to judge every proposal against the ideal .... When you're governing, you first have to ask, `Can it pass?' And then you've got to ask, `Well, how does it compare to doing nothing?"' said Neil Bradley, a former House GOP aide who's now a top policy expert at the U.S. Chamber of Commerce. "They haven't quite made the adjustment from judging things against the ideal to judging proposals against doing nothing."
Few congressional Republicans have experience serving under a Republican president — just 59 of 237 House Republicans served in the majority under former President George W. Bush in the early-to-mid-2000s.
Because they are unfamiliar with their new set of circumstances, some tea party purists — used to having their way or picking up their marbles and quitting the game — are now struggling with demands that they compromise.
Strains are already showing, as Republicans promising to repeal and replace Obama's health care law simultaneously — backed by President Donald Trump — are at odds with conservative purists like Sens. Rand Paul, R-Ky., and Ted Cruz, R-Texas, who are sticking to last year's script of killing Obamacare outright without a GOP substitute at hand.
In a made-for-the-media move last week, Paul took reporters door to door in the Capitol looking for the House GOP's health care bill and openly warned that he had the votes to kill it in the Senate.
In the House, hard-right Freedom Caucus members — that's the group that marched former Speaker John Boehner into a 2013 government shutdown and later toppled him — are battling against elements of the GOP leadership's emerging health care draft such as refundable tax credits to buy insurance. If they're unbending, it could be the death knell for the GOP's health care efforts.
"Statements by small groups of Republicans saying, `Well, this is not acceptable to me' — and that becomes how you negotiate — that's just not a way to get to 218," said GOP loyalist Rep. Tom Cole of Oklahoma, referring to the magic number to pass legislation in the 435-seat House. "You can argue with the quarterback in the huddle, but once you go to the line you really need to execute the play."
What is more, circumstances are more difficult now than they were during the most recent successful burst of Republican-sponsored domestic legislation, when a unified Republican government in the early 2000s produced tax cuts, a major education bill, and the Medicare prescription drug benefit.
That spate of Bush-era domestic successes was produced by a narrow but battle-hardened House GOP majority that had experience in running the House on a tiny margin. House GOP leaders and committee chairmen were more seasoned and powerful. And key Senate Democrats like John Breaux of Louisiana were willing partners.
At the same time, the goals of congressional Republicans and Trump are more challenging. Taking benefits away from people — as in Obamacare repeal — is generally more difficult than doling them out. Picking winners and losers in tax reform is far more difficult than cutting taxes outright.
Republican veterans say the challenges of the moment cry out for a rebirth of GOP teamwork, abandoning Obama-era infighting, and a more leadership-driven Congress.
"They've got a moment in history. They'd better take advantage of it and not mess it up," said former Senate Majority Leader Trent Lott, R-Miss., who helped shepherd the Bush tax cuts through the Senate. "Once the Speaker pulls the trigger and say's let's go, we've got to do this,' they've got to get in line."