Is Trump running for president or Godfather?

The mercurial Mr. Trump vowed he would get along with Congress and Speaker Paul Ryan – or Ryan would "pay a big price." 

Is this another one of Trump's empty threats?  Or can he really damage Ryan politically?

Marketwatch:

Donald Trump believes he’ll get along great with House Speaker Paul Ryan. And if not? Look out.

Trump, who won commanding victories in Super Tuesday primaries and marched closer to the Republican presidential nomination, answered reporters’ questions about how he’d work with members of Congress if he wins the White House.

“I’m going to get along great with Congress, OK? Paul Ryan, I don’t know him well, but I’m sure I’m going to get along great with him, and if I don’t? He’s gonna have to pay a big price, OK?”

Ryan, a Wisconsin Republican, had earlier Tuesday taken a shot at Trump by saying the party’s nominee must reject the support of bigots. Ryan didn’t mention Trump by name but it was clear who he was talking about. Ryan slammed the candidate for not distancing himself from the support of former Ku Klux Klan leader David Duke. Trump blamed a “bad earpiece” for declining to disavow Duke in an interview last weekend.

Trump’s language on Tuesday night had more than one observer likening the real-estate mogul to a character from the “Godfather” movies.

Trump says Paul Ryan will get along w/him orbpay a big price. He does realize he's running for president and not godfather? #NeverTrump

— NoDrumpf/NoHillary (@TroompaLoompa) March 2, 2016

"Play nice if ya know what's good for ya, Fredo. Otherwise you might not like how it goes." - Donald "Vito" Trump https://t.co/2lLpeRSGLz

— Huxley's Ghost™ (@AF632) March 2, 2016

Godfather pt 4: Trump: I'll get along with Paul Ryan. Or he'll "pay a big price."

— Gary Armstrong (@vanityman) March 2, 2016

Does Trump realize that his tone is offensive?  Probably not.  His tactics resemble those of a schoolyard bully, which works great in the rough-and-tumble world of real estate but doesn't translate well into the world of politics.  In fact, that tone would make some politicians resentful – not the best way to "unify" the Republican Party.

Is this the way it will be if Trump is elected president?  He certainly won't win many friends by employing tactics that embarrass and humiliate people he should get along with.