(CNN) Washington Republicans have spent long stretches of the past 10 months -- their first with unified control of the federal government in a decade -- alternately contending with and rationalizing President Donald Trump's erratic behavior.

That those competing impulses should clash so dramatically, with a former top administration official standing in court on the same day long-desired tax cuts near passage, is a coincidence befitting the opportunity and peril Trump represents for his party.

Some Republicans have groused about him in private, others scolded or lamented him in public remarks; most dodged or demurred when confronted with the controversy du jour. When compelled, a few might issue censorious statements or tweet their concerns. But Trump has carried on, spitting Twitter venom at political foes (and allies he felt slighted by), seemingly oblivious to -- or actively spiteful of -- the sensitive mechanisms and relationships that typically drive policy-making on Capitol Hill.

Republicans in the Senate, and a handful in the House, have been subject to routine humiliations and insults from their President, even as his own team, including campaign officials and his former national security adviser, came under increasing scrutiny for their alleged ties to Russia.

After Obamacare repeal failed and his agenda looked to be falling apart, Trump pressed on, personally demeaning GOP officials who crossed him. Senate Majority Leader Mitch McConnell, Sen. John McCain, Sen. Jeff Flake, Sen. Bob Corker -- the list goes on -- have all come under attack. The latter pair will retire rather than seek re-election in 2018.

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