At the heart of the infamous Ukraine phone call that prompted House Democrats’ impeachment inquiry is President Trump’s vow to get to the bottom of the origins of the Russia probe, which dominated the first two-plus years of his presidency.

In trying to uncover how the “witch hunt” began, Mr. Trump now faces a bigger political crisis.

The Trump campaign came out swinging this weekend against impeachment, launching a $10 million TV and digital ad accusing Democratic front-runner Joseph R. Biden of meddling in Ukraine. Political insiders say it’s a strong indication of how Mr. Trump intends to fight back.

“He’ll be very aggressive,” said Republican strategist John Feehery. “I think ultimately his game plan is to make sure the base is with him. He understands this is a political fight, not a legal fight, and he’s going to play politics. He knows that if he loses the base, he loses the game.”

Mr. Trump and his aides in the early days of the crisis have gone on the attack against an unnamed government whistleblower who prompted the charges while also firing back at House Speaker Nancy Pelosi, and Chairman Adam B. Schiff of the House Permanent Select Committee on Intelligence. The White House message is that this latest political peril for Mr. Trump is all part of the same partisan hatred that has dogged him from the start.

“There are no high crimes and misdemeanors here,” said White House senior counselor Kellyanne Conway. “People were talking about impeaching this president before he even got inaugurated. And now they’re getting their wish. Nancy Pelosi finally capitulated to her angry mob.”

She said the American people “will see what’s not getting done” in Congress while Democrats devote their attention to impeaching Mr. Trump in a strong economy.

The president also echoed a prediction Sunday by Republican National Committee Chair Ronna McDaniel that the Democrats’ impeachment effort will backfire, especially in Democratic House districts that Mr. Trump won in 2016.

“Will happen to all of those seeking unlawful impeachment in 50 Trump type Districts,” the president tweeted. “We will win big!”

In trying to sustain his 2020 reelection bid, Mr. Trump is still fighting a battle over his 2016 campaign.

The president’s phone call with Ukraine President Volodymyr Zelensky on July 25 started with pleasantries, but quickly shifted Mr. Trump’s interest in a missing Democratic National Committee server that was hacked by Russia during the 2016 election.

“I would like you to find out what happened with this whole situation with Ukraine … The server, they say Ukraine has it,” the president told Mr. Zelensky.

He also mentioned the U.S. cybersecurity firm CrowdStrike, which the DNC hired in 2016 to investigate the breach of its servers and first reported Russia as the culprit.

The president’s conversation took place a day after special counsel Robert Mueller testified to Congress, an appearance that was criticized as weak. Mr. Mueller did confirm the findings of his report, which found no collusion between the Trump campaign and Russia in the election.

“As you saw yesterday, that whole nonsense ended with a very poor performance by a man named Robert Mueller, an incompetent performance,” Mr. Trump told Ukraine’s leader. “But they say a lot of it started with Ukraine. Whatever you can do, it’s very important that you do it if that’s possible.”

The Justice Department has announced that U.S. Attorney John Durham, who is investigating the origins of the FBI’s “Crossfire Hurricane” probe into alleged links between the Trump 2016 campaign and Russia, was already looking into whether the Ukrainian government led by then-President Petro Poroshenko was involved in the effort to torpedo Mr. Trump’s candidacy.

Mr. Zelensky raised the name of the president’s personal lawyer, Rudolph W. Giuliani. Mr. Giuliani had canceled a trip to Ukraine last spring to investigate whether the previous Ukrainian administration helped Democratic candidate Hillary Clinton’s presidential campaign by providing information concerning former Trump campaign chairman Paul Manafort’s lobbying work in the country.

Mr. Giuliani also was probing why Ukraine fired Prosecutor General Viktor Shokin, who had been looking into Hunter Biden’s lucrative position with a Ukrainian energy company.

“This is what they [Democrats] did to Manafort,” said veteran Washington lawyer John Dowd, who represented the president in the Mueller probe. “They went overseas and they dug all this stuff up. What’s good for the goose is good for the gander.”

The Hill reported in May that the Ukrainian Embassy in Washington said a Democratic National Committee contractor solicited dirt on Manafort during the 2016 campaign and even tried to enlist the country’s president to help.

The contractor later tried to arrange for Mr. Poroshenko to comment on Manafort’s Russian ties during a visit to the U.S. during the 2016 campaign, the Ukrainian ambassador said.

As for Mr. Trump’s request for Ukraine to investigate the Bidens, the president’s conservative allies also believe there is a potential connection to the origins of the Russia allegations against Mr. Trump.

“Biden was responsible for U.S. policy in Ukraine during the Obama administration, and much of the false narrative about President Donald Trump being a Russian agent came from Ukraine, the United Kingdom and other Western intelligence agencies, which his administration put a bow on and shipped to the FISA court so they could spy on the Trump campaign in 2016,” said Rick Manning, president of Americans for Limited Government. “What did Joe Biden know about Russiagate and when did he know it?”

The president also has directed most of his campaign criticism at Mr. Biden, perceiving him as his likeliest — and probably toughest — opponent in the general election. He’s gone to considerable lengths to take him out early during the Democratic primary, openly questioning his fitness for office.

“I think he’s the weakest mentally, and I like running against people that are weak mentally,” the president said of Mr. Biden last summer.

Democrats are using the president’s effort to investigate the Bidens in Ukraine as their primary argument for impeachment, accusing the president of seeking foreign help in interfering in a U.S. election. Mr. Biden is, for now, still the front-runner for the Democratic nomination.

At the time of the phone call with Mr. Zelensky, Mr. Trump was withholding military aid to Ukraine.

“I think we have to stay focused as far as the public is concerned on the fact that the president of the United States used taxpayer dollars to shake down the leader of another country for his own political gain,” House Speaker Nancy Pelosi said Friday.

Mrs. Pelosi also suggested that Russia played a role in the saga.

“It is wrong for any foreign government to interfere in our elections and here you have the president of the United States asking for that,” she said without elaborating. “I think Russia has a hand in this, by the way.”

The White House ended the week with Mr. Trump declaring “we’re at war” with the Democrats. The president and his allies were also questioning the motives of the unnamed government whistleblower, who’s reportedly a CIA officer.

Mr. Trump last week also suggested he could go to court to stop the Democrats.

“There should be a way of stopping it, maybe legally through the courts,” Mr. Trump said.

Even some Republicans close to the White House say impeachment is a real concern.

“I think there’s a good chance of impeachment,” said one administration ally. “Will he be removed [by the Senate]? No. Will he even care? I think he thinks it would be one more big reality TV moment, and he’s the star of it.”

Sign up for Daily Newsletters Manage Newsletters

Copyright © 2020 The Washington Times, LLC. Click here for reprint permission.