ANALYSIS: President Trump preps for war with own base The fate of Obamacare repeal rests at his own fingers for tweeting.

 -- We’ve seen him play the bully before. But how does the bully pulpit work against his own base?

That question now defines the stakes for Donald Trump’s presidency. His decision to march into the battle over health care alongside House GOP leaders – with no clear path to a bill-signing ceremony – places them in an uncomfortable alliance with the White House, with their own rank and file as the enemy.

Responses to the American Health Care Act have been immediate and fierce. AARP, the American Medical Association, the House Freedom Caucus, GOP Sens. Rand Paul and Ted Cruz, Laura Ingraham, Ann Coulter, the Heritage Foundation, the Club for Growth, tea party groups, the Koch network and even the Trump-friendly Breitbart News have lined against the president’s replacement plan for Obamacare.

On one level, this puts the fate of the biggest-ticket item on the GOP agenda squarely where Trump wants it: in his own hands, and at his own fingers for tweeting. He has battled and defeated Republicans before, with bigger consequences even than in the fight over Obamacare.

“We’re going to have a full-court press,” White House press secretary Sean Spicer said today.

Yet beyond the ironies of Trump and House Speaker Paul Ryan’s teaming up to push a bill that still has no cost estimate or a calculation about how many people will be affected, the president is embarking on a mission that is starting by testing the allegiance of his base.

“This is all hands on deck,” Ryan said today, calling the vote-gathering effort a “team sport.”

It is an odd team. Ryan famously resisted Trump’s takeover of the Republican Party longer than almost anyone else in a position of power. He is now relying on the White House to deliver votes in his own House.

In the Senate, where Republicans have a smaller margin for defections, the bill is running into staunch conservative opposition. Any movement in the direction of Paul and Cruz, moreover, risks alienating moderates, including those most worried about being re-elected.

So far, Trump is employing charm rather than threats. He and Vice President Mike Pence are meeting with some of the most skeptical House Republicans, and the president is scheduled to host Cruz and his wife for dinner tonight.

Trump even sent a good-natured tweet directed at “my friend” Rand Paul, saying he’s confident that Paul will “come along with the new and great health care program because he knows Obamacare is a disaster!”

Agreement on that last point has never been an issue for Republicans. That’s just one reason this push will have longer-term consequences: This is where Republicans appeared to agree, unlike on immigration, trade or foreign policy, where Trump’s positions are more fundamentally challenging to GOP dogma.

We’re about to find out what Trump really wants out of his presidency. Pushing legislation as he campaigned and as he has governed so far would suggest a scorched-earth drive that spares no friends and respects no party lines.

A traditional presidency could expect to be crippled by a loss on something as big as a health care overhaul, this early in a term. It’s worth remembering, though, with Trump staring down what could be his first major legislative setback, that this not a traditional presidency.