The Note: Why is Trump eating his own in the Republican Party?

— -- WHAT YOU NEED TO KNOW TODAY

THE TAKE with ABC News' Rick Klein

Does President Trump want to be president, or does he want to be Trump? His behavior, combined with the lay of the political land, suggests that he won't be able to do both – not simultaneously, and not if his goal is governing as opposed to building himself up. He is taunting his own party – the party that controls all of Washington – with the prospect of a government shutdown that nobody wants, to pay for a wall he guaranteed Mexico would. He's flirting with the economic calamities surrounding the debt ceiling by casually tossing told-ya-so's into the political ether, knowing that it's his own party that resists fast, clean action. Senate Majority Leader Mitch McConnell is publicly trying to turn down the heat of his unusual feud with the president; Trump is using Twitter to turn it right back up again. Strikingly, White House press secretary Sarah Sanders' response to Sen. Bob Corker – the chairman of the Senate Foreign Relations Committee, and a former vice presidential and secretary of state short-lister, was that he isn't worth a response at all: "A ridiculous and outrageous claim and doesn't even require a response from this podium." The Tennessee senator said last week that Trump has yet to demonstrate the stability or competence needed to be successful. If Trump wants true independence from GOP elected leadership, or even if he doesn't, he may well be getting it. "We are the party of the Union, and he is the most divisive president in our history," former Sen. John Danforth, R-Mo., writes in a stinging Washington Post op-ed. "Our party has been corrupted by this hateful man, and it is now in peril."

THIS WEEK ON "THIS WEEK"

The Powerhouse Roundtable debates the week in politics, with ABC News political analyst Matthew Dowd, host and managing editor of "News One Now" Roland Martin, Associated Press Washington bureau chief Julie Pace, former Obama State Department spokesperson and CNN contributor Jen Psaki, and ABC News contributor and Newsmax Media CEO Christopher Ruddy.

QUOTE OF THE DAY

"I think the relationships are fine. Certainly, there are going to be some policy differences..." -- Press secretary Sarah Sanders on Trump's relationship with Sen. Mitch McConnell

NEED TO READ with ABC News' Daksha Sthipam

White House dodges questions on why Trump threatened shutdown over wall funding. White House press secretary Sarah Sanders dodged questions Thursday afternoon on why President Trump threatened a government shutdown over funding for his promised border wall, after repeatedly insisting that it will be paid for by Mexico. "The president's committed to making sure this gets done. We know that the wall and other security measures at the border work," Sanders said in response to an inquiry from ABC News Chief White House Correspondent Jonathan Karl. http://abcn.ws/2vtND34

What you need to know about the government shutdown showdown. President Trump's threat Tuesday to force a government shutdown over the battle to pay for his promised southern border wall raised concerns on Capitol Hill among legislators who fear that the fight for funds could turn into a hostage situation. It's been four years since the last federal government shutdown and would be the first time under Republican control of the White House, Senate and House. http://abcn.ws/2xgLhX9

Mystery surrounds injuries to at least 16 US officials in Cuba. ABC News

Trump to push for tax reform passage by year's end, says Cohn. The Financial Times

John Kelly's latest mission: Controlling the information flow to Trump. The New York Times

The Note is a daily ABC News feature that highlights the key political moments of the day ahead. Please check back Monday for the latest.