WASHINGTON — At the heart of the impeachment case against President Donald Trump lies a potential dagger for his re-election campaign: He’s accused of putting himself first — and American interests second.

So the president’s problem isn’t just that the Ukraine affair has potentially provided the House with the substance of an impeachable offense. It’s the fact that the very same alleged activity — abusing his office to help himself — cuts against his core political message of always placing “America first.”

“The more we read about this story, it highlights what we’ve come to know over the last couple of years, which is he might be in the Hall of Fame of self-interest,” said Purple Strategies Managing Director Rory Cooper, a former House GOP leadership aide who argued Tuesday that Republicans must publicly describe the president’s conduct as wrong.

Cooper recalls Trump running in 2016 on “the idea that he was going to fight for people that no one else was fighting for” while he portrayed his opponent, Hillary Clinton, as corrupt and self-dealing.

“The only ‘victim’ that Donald Trump is fighting for anymore is himself,” Cooper said.

Incredibly, it was Trump’s White House that voluntarily released the summary of a phone call transcript containing what his critics point to as plain evidence of misplaced interests — a release that was reportedly at odds with the instincts of more seasoned political players like Vice President Mike Pence.

Perhaps Pence understood that evidence that Trump was using the power of the presidency to try to secure his own re-election — or even just boosting the perception that he tried to do that — could be devastating in the midst of an impeachment push by House Democrats and as the two men campaign for a second term.

Since 2014, Congress has provided about $1 billion in aid to Ukraine to counter Russian aggression — a policy deemed to be in the national security interests of the U.S. by lawmakers and both the Obama and Trump administrations. But for several months this year, the Trump administration withheld a planned $391 million injection of support to Ukraine without explanation. Then, in September, after a phone call between Trump and Ukrainian president Volodymyr Zelenskiy, Trump released the money.

When the money was headed to Ukraine, that was in America’s stated interest.

In holding it back, Trump was subordinating that interest to something else — but not explaining his motives publicly or to Congress.

“I have no idea what precipitated the delay,” Senate Majority Leader Mitch McConnell, R-Ky., who was a major advocate for providing the money, told reporters late last month.

The summary of his remarks in the phone call conversation provided a possible answer.

“I wouldn’t say that it’s reciprocal necessarily because things are happening that are not good but the United States has been very very good to Ukraine,” Trump said early in the call.

Zelenskiy replied by praising Trump for the U.S. effort to assist Ukraine and noted that “we are almost ready to buy more Javelins [a type of missile] from the United States for defense purposes.”

Trump then asked Zelenskiy for two things: facilitation of efforts by Attorney General William Barr and Trump’s personal lawyer, Rudy Giuliani, to investigate the company Crowdstrike, and an investigation into former Vice President Joe Biden — Trump’s top rival for the presidency in 2020 — and his son, Hunter Biden.

After the phone call with Zelenskiy, in which he was assured that the new prosecutor would play ball, Trump released the $391 million. That decision realigned U.S. policy with stated U.S. interests in the region. The question Democrats are asking now — and in some cases phrasing directly as an accusation — is whether the order of operations shows that Trump used his authority to put own interests ahead of his country’s.