So much for Joe Cool.

President Trump’s campaign pointed to Joe Biden’s snarling response to a question about his son’s Ukraine business dealings as evidence that the former vice president has a guilty conscience.

“What is he hiding?” the Trump War Room Twitter account asked after a video clip of Biden at a Friday press conference in LA went viral.

CBS News reporter Bo Erickson set Biden off when he asked whether son Hunter Biden’s lucrative job with an oil company owned by an oligarch accused of corruption posed a conflict of interest for Biden.

The ex-veep was point man for the Obama administration’s Ukraine policy when his son got hired as a $50,000-a-month board member at Burisma Holdings.

“It’s not a conflict of interest,” Biden snapped. “There’s been no indication of any conflict of interest from Ukraine or anywhere else. Period.

“I’m not gonna respond to that,” he continued, voice raised, as he jabbed a finger at the reporter. “Let’s focus on the problem, focus on this man, what he’s doing, that no president has ever done. No president!”

It was the second time in two weeks that Biden berated a journalist for querying him about his son’s Ukraine entanglements.

“You should be looking at Trump,” Biden barked during a Sept. 21 press gaggle. “Ask the right question.”

“Biden bullies the press,” wrote Matt Wolking, the Trump campaign’s deputy communications director, in an e-mailed statement. “Quid Pro Joe clearly has no good explanation for what many independent observers say was an obvious conflict of interest.”

Trump retweeted a Fox News segment on the video Saturday.

As House Democrats aim their impeachment inquiry at Trump, the investigation has cast a spotlight on Ukraine and its long history of government corruption.

Biden in 2016 allegedly threatened to rescind Ukraine’s $1 billion in loan guarantees if the government didn’t oust Viktor Shokin, the country’s top prosecutor, who had targeted Burisma.

Biden denies the story, but the charge continues to dog him. A Monmouth poll released Tuesday found 43 percent of Americans believe it — and that’s had an impact on his primary campaign.

Biden was the clear front runner in May, when he held a commanding 27-point advantage over second-place Sen. Bernie Sanders, but he now hold just a two-point lead over Sen. Elizabeth Warren, according to the RealClearPolitics polling average.

And Warren tops him in the two most recent national polls, both released Wednesday.

Biden’s fundraising is also flagging. Third-quarter figures released this week show that he pulled in $15.2 million in the last three months, a haul that placed him a distant fourth behind Sanders’ $25.3 million, Warren’s $24.6 million and South Bend mayor Pete Buttigieg’s $19.1 million.