(CNN) Senate Republicans won a relatively minor but important legislative victory on health care on Tuesday afternoon. But the lengths they had to go to secure it -- John McCain flying back from Arizona fewer than two weeks removed from surgery that led to a brain cancer diagnosis -- suggest the problems, political and policy-wise, that await congressional GOPers and the Trump White House.

Republicans woke up Tuesday morning faced with the possibility that, even with McCain's return to Washington, they would not be able to secure the votes they needed to merely bring the health care bill to the floor and allow it to be debated.

In the usual legislative cycle, the "motion to proceed" -- which is what Republicans passed Tuesday -- is merely a formality. But, as with all things related to health care, it became a nail-biter as Vice President Mike Pence broke a 50-50 Senate tie to pass it.

In clearing that hurdle, Senate Majority Leader Mitch McConnell avoided a massive embarrassment and President Donald Trump avoided a stunning rebuke from his own party. Both men had leaned hard on wavering senators over the past few days.

McConnell, as usual, took the more behind-the-scenes route to do his persuading. Trump, again, as usual, went the public route. "Any senator who votes against starting debate is telling America that you are fine with the Obamacare nightmare, which is what it is," he said on Monday.

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