President Trump may have bruised his relationship with indispensable Republican mega-donor Sheldon Adelson, reports Politico — alarming GOP officials at a “precarious moment” in the 2020 campaign.

Describing Adelson, 87, as “perhaps the only person in the party who can cut a nine-figure check” to help re-elect Trump, the political website says Adelson reached out to the president by phone last week to discuss Covid-19 relief legislation and the overall economy.

But the call “unexpectedly turned contentious,” Politico says, citing three sources “with direct knowledge of the call.”

Trump seems to have been unaware of how important Adelson, a casino magnate and one of the world’s richest people, is to the party and to his chances against Joe Biden.

In the midst of the phone call, “Trump brought the conversation around to the campaign and confronted Adelson about why he wasn’t doing more to bolster his reelection,” Politico says.

One of the website’s sources said “it was apparent the president had no idea how much Adelson, who’s donated tens of millions of dollars to pro-Trump efforts over the years, had helped him.”

Rather than firing back, Adelson apparently chose to hold his tongue.

But on learning of the call, Republican leaders feared Trump had ignorantly scorned one of his biggest benefactors.

Adelson associates can’t say whether the call will dissuade the Las Vegas billionaire — “long regarded as a financial linchpin for Trump’s re-election” — from helping him in the stretch run of the campaign.

But one thing is clear, Politico says: “The president needs the money.”

That’s because liberal super PACs supporting Biden are outspending pro-Trump groups by nearly 3-to-1, with the election less than 3 months away.