U.S. President-elect Donald Trump (L) meets with Speaker of the House Paul Ryan (R-WI) (C) and Vice-President elect Mike Pence on Capitol Hill in Washington, U.S., November 10, 2016. REUTERS/Joshua Roberts President-elect Donald Trump, left,  with House Speaker Paul Ryan (R-Wis.) and Vice President-elect Mike Pence. (Joshua Roberts/Reuters)

A single, unidentified source, according to the New York Post, says President-elect Donald Trump told Sen. Chuck Schumer (D-N.Y.) that he likes him better than Senate Majority Leader Mitch McConnell (R-Ky.) and House Speaker Paul D. Ryan (“he likes Schumer more than Ryan and McConnell because they both wanted him to lose”). We cannot tell if Trump actually said it, let alone meant it, let alone will mean it a week or a day from now. (Operating off a single blind source in the Trump administration would seem to be the definition of reckless, by the way.) One could imagine Trump saying something like this, although of course Schumer wanted Trump to lose, also. Welcome to Trump politics — irrational, personalized, mercurial, vengeful and maybe fictionalized by media straining for insights into the new administration.

One thing we can be sure of: At some point Trump will decide Schumer is a “loser” or “the worst” or whatever childish insult comes to mind because Schumer and Trump do not share objectives. As self-evident as it may be, Trump operates in a world in which someone’s worth (whether it is Schumer or Ryan or Russian President Vladimir Putin) is a direct reflection of whether he is saying nice things about Trump. This may be one reason he relies so heavily on his children; they know better than to insult him or to challenge him in ways that prompt him to lash out. (They are, in a word, enablers.)

The natural tendency is to think: Why, that can’t be! That’s grade school stuff. How can any adult, let alone the president, operate like that? But, of course, it can be, and Trump has consistently operated that way, at least until now. For a textbook narcissist, there is no objective, ideology, aim or vision other than satisfaction of his own ego. It makes him a sitting duck for flattery — and may make him a very isolated president, very quickly.

Interestingly, news reports also suggest Schumer and his Democratic colleagues are preparing to “target” up to eight Cabinet nominees. That may mean anything from tough questioning to a real national campaign to block an exceptionally problematic nominee. For the sake of party unity and morale, they will need to fight hard against nominees such as attorney general pick Sen. Jeff Sessions (R-Ala.) and Labor Department choice Andy Puzder. Because the Trump team was apparently light on vetting, and a CEO billionaire like Puzder may have significant financial conflicts he must resolve, there is always the potential one or more nominees blow up in the confirmation process. Realistically, however, both of these nominees have near-solid Republican support, so barring unexpected revelations or a rocky confirmation hearing (both are entirely possible), they should get through.

President-elect Donald Trump has picked Rex Tillerson as his nominee for secretary of state. Here's what you need to know about Tillerson. (Thomas Johnson,Victoria Walker,Danielle Kunitz/The Washington Post)

Now, when Schumer delays the confirmation process or maybe even derails a nominee (perhaps the secretary of state pick, ExxonMobil Chief Executive Rex Tillerson, with the help of dismayed GOP hawks), Trump won’t be whispering sweet nothings to any Democrat. He’ll be flailing away on Twitter, denouncing Schumer & Co. as he does anyone who gets the better of him.

Likewise, if, for example, the GOP House refuses to do his bidding on a tariff bill or won’t pass an overstuffed infrastructure bill consisting of tax breaks for billionaire developers, Trump’s newfound affection for Ryan will evaporate as well. He’ll be back to calling Ryan “very weak and ineffective” or “a man who doesn’t know how to win.” His new cordial relationship with Mitt Romney? If Romney starts speaking up about Russia, Trump surely will revert to labeling him a “catastrophe” who was “just trying to stay relevant.”

Sooner or later, everyone is bound to be a “loser” or “horrible,” according to Trump. That makes it tricky to sustain ongoing relationships for four years with these people. Unlike on reality TV, he cannot fire Schumer, Ryan or McConnell. He already has historically low favorability, so his ability to go over their heads to the public is somewhat limited. (Moreover, are Sens. Rob Portman, Pat Toomey, Marco Rubio or other freshly elected or reelected senators going to care if they get mass emails and nasty calls form Trumpkins?)

The president has formidable powers, to be sure. We already have seen how Republicans are deferring to him even on matters such as his gross conflicts of interest. Republicans nevertheless are not going to give way on everything. Russia will be an interesting, early test. If there is a vast majority in both houses for additional sanctions, does Trump declare 90 percent of lawmakers to be “terrible” or “a disaster”? (Maybe he pulls another Trump tactic — gaslighting the press and public, pretending he wasn’t opposed to sanctions.)

We don’t expect that a 70-year-old billionaire who just won the presidency is going to change, but his persona (a mix between Tony Soprano and Miranda Priestly from “The Devil Wears Prada”) poses some, well, unique and fascinating challenges. Without a single hapless opponent to crucify, Trump’s reflex reaction to opposition — obsessively attack and demean critics — may be his biggest obstacle to governing in a system that generally requires cooperative action.