President Trump’s legal team set about making his impeachment trial about the Bidens on Monday, with former Florida attorney general Pam Bondi offering an extensive case for why Trump’s interest in the investigation was legitimate.

Trump’s Senate allies had in recent days been advising the defense team to hone in on the Bidens and Burisma Holdings, the company that employed Hunter Biden.

“I told them, look, nothing matters more than the facts on Burisma,” Sen. Cruz (R-Tex.) told conservative radio host Hugh Hewitt on Friday, adding: “They built their entire case on this house of cards. Lay out substantive, factual reasons why investigating Burisma — the president had a responsibility to do so.”

Their argument would be that Trump’s concerns about the Bidens and Burisma were legitimate, and so would have been his efforts to secure an investigation into them.

But if the Democrats’ argument is built on a house of cards, what are the allegations against the Bidens built on? Below are some basics about the Bidens, Burisma and the Trump team’s allegations involving them.

What is Burisma?

Burisma Holdings is an oil and natural gas company based in Ukraine. It is run by oligarch Mykola Zlochevsky, who according to a recent ranking is among the 10 wealthiest people in the country. Ukraine has struggled with corruption for decades — it is often ranked as the most corrupt country in Europe — and Zlochevsky, too, has been accused of corruption.

State Department official George Kent testified in November that he believed Zlochevsky was involved in “self-dealing” when he served as Ukraine’s minister of ecology and natural resources between 2010 and 2012. “He used his regulatory authority to award gas exploration licenses to companies that he himself controlled,” Kent told the House impeachment inquiry. “That would be considered an act of corruption in my view, yes.”

How do the Bidens come in?

Hunter Biden was hired to serve on Burisma’s board of directors in 2014, when his dad was vice president.

What is the allegation involving the Bidens?

In a phone call with Ukraine President Volodymyr Zelensky on July 25, Trump suggested that then-Vice President Joe Biden’s efforts in 2015 and 2016 to remove Ukraine’s then-top prosecutor, Viktor Shokin, were aimed at benefiting his son, because the prosecutor had been investigating Burisma.

“ … There’s a lot of talk about Biden’s son — that Biden stopped the prosecution, and a lot of people want to find out about that,” Trump told Zelensky, adding: “Biden went around bragging that he stopped the prosecution, so if you can look into it … It sounds horrible to me.

Biden had indeed bragged about successfully pressuring Ukraine to oust Shokin. At a January 2018 event hosted by the Council on Foreign Relations, he described threatening to withhold U.S. loan guarantees if Shokin stayed. He did not brag, though, about stopping any prosecution involving Burisma.

Is there anything to the allegation?

There are plenty of other reasons the theory does not add up.

Crucially, U.S. and Ukrainian sources have told The Washington Post and other outlets Shokin was not actively investigating Burisma at the time of his ouster.

Opposition to Shokin was also a clear policy of the Obama administration and had been for some time. In September 2015, then-U. S. Ambassador to Ukraine Geoffrey Pyatt blasted Shokin, citing “the failure of the institution of the prosecutor general of Ukraine to successfully fight internal corruption.” He added: “The United States stands behind those who challenge these bad actors.” The next month, then-Assistant Secretary of State Victoria Nuland testified to the Senate that Shokin’s “office has to be reinvented as an institution that serves the citizens of Ukraine, rather than ripping them off.”

In fact, as The Post has reported, one of the objections to Shokin was that he was not harder on Zlochevsky:

In particular, Pyatt singled out the office for its failure to provide sufficient information to British authorities to justify their freeze of Zlochevsky’s funds, one reason the U.K. court ultimately released them.
Instead, the Ukrainians “sent letters to Zlochevsky’s attorneys attesting that there was no case against him,” Pyatt said.
Pyatt called for officials who wrote the letters to be investigated and for those responsible for “subverting the case” against Zlochevsky to be fired.

Joe Biden and the U.S. government were hardly the only ones pushing for Shokin’s ouster. This was a consensus of Western allies of Ukraine, as well as the International Monetary Fund and the World Bank.

In other words, everyone wanted Shokin out because he was actually too soft on corruption — and thus allegedly corrupt himself — which suggested Burisma was not in any great danger with him as prosecutor general and might have been better off.

But isn’t there a conflict of interest?

At the very least, Hunter Biden being employed in a country in which his father was engaged in high-stakes foreign policy was problematic. Both he and his father have acknowledged that, to varying degrees.

Hunter Biden said in October he would not do any foreign work if his father becomes president, and Joe Biden said in December he would not let his kids cash in on his name and work overseas if he is president.

We know Ukrainians who were concerned about corruption were nervous about the appearance of Hunter Biden joining the Burisma board. The Post’s Paul Sonne, Michael Kranish and Matt Viser wrote in September:

For some Ukrainians, Hunter Biden’s association with Burisma undermined his father’s calls to end corruption in Ukraine. It also raised concerns that prosecutors would avoid pursuing alleged wrongdoing by Zlochevsky out of fear that the former minister had high-level connections in the United States — the critical backer of the Ukrainian government at the time.

At least some concerns were also raised within the Obama administration about Hunter Biden’s employment at Burisma. Kent, the top State Department official, testified that he lodged his complaint with the vice president’s office in early 2015, but that he was rebuffed and told the elder Biden could not deal with it because his other son, Beau, was dealing with cancer. (Beau Biden died in 2015.)

So what does it mean for Joe Biden?

Importantly, that last one — Kent’s complaint — is about the only proved, problematic thing that has been tied to Joe Biden’s actions or his office. But it is not even clear that it was brought to his attention. Everything else is guesswork based upon suppositions that do not jibe with the other, known evidence.

It is possible Burisma is corrupt and Hunter Biden made a bad decision by working there, but there remains no evidence Joe Biden’s actions were influenced by personal interest. In fact, they were in line with both the rest of the Western world and administration policy, and there is no evidence that his actions carried a material benefit for his son. There are actually compelling reasons, in fact, to believe they might have put Burisma in more jeopardy.

Is Trump just concerned about corruption?

However tenuous the Burisma allegation is, the question remains: Is it worth looking into? Maybe Trump is just that concerned about corruption, that he truly wants to make sure.

That is seriously questionable, though, based on the evidence. Trump has often looked past human rights violations and corruption, believing them to be obstacles to doing business with other countries. He has seldom even talked about corruption in other countries — even ones more corrupt than Ukraine that receive more U.S. funding. The only two investigations he has pushed for in Ukraine carry obvious political benefits for him: one by tarring the Bidens and the other by potentially shifting blame for 2016 election interference from Russia (whose role Trump has cast doubt upon) to Ukraine.

In his conversations with Zelensky, Trump has also declined to raise the broader concept of corruption. A readout of his earlier, April call with Zelensky indicated they had talked about corruption. But a transcript later furnished by the White House showed they actually did not — even though talking points given to Trump said he should, according to testimony from White House aide Lt. Col. Alexander Vindman.

David Holmes, a U.S. aide in Ukraine, also testified that Trump’s ambassador to the European Union, Gordon Sondland, told him Trump did not actually care about Ukraine’s fate, that he did not “give a s---” about the country.

“I asked why not, and Ambassador Sondland stated that the President only cares about ‘big stuff,’ ” Holmes testified. “I noted that there was ‘big stuff’ going on in Ukraine, like a war with Russia, and Ambassador Sondland replied that he meant ‘big stuff’ that benefits the President, like the Biden investigation that Mr. Giuliani was pushing.”

Why is this coming up now?

It is one of the most conspicuous questions. Remember this was going down between 2014 and 2016, when Biden was still vice president. Kent was not the only one to raise the issue. Reports in publications including the Wall Street Journal (“Ukrainians See Conflict in Biden’s Anticorruption Message”) and The Washington Post (“Hunter Biden’s new job at a Ukrainian gas company is a problem for U.S. soft power”) raised possible issues with Hunter Biden’s employment with Burisma.

There is no evidence Republicans pressed the issue then — even after Joe Biden pushed Shokin out. In fact, some Republican senators were very much onboard with the idea that Shokin was not getting the job done. Sens. Ron Johnson (R-Wis.) and Rob Portman (R-Ohio) both signed a letter urging reforms to the prosecutor’s office shortly before Shokin was pushed out.

The issue did come up, however, shortly after Biden launched his presidential campaign last year, within a couple of days. Biden announced he was running on April 25, the New York Times story came out May 1, and Giuliani was planning a (later-canceled) trip to Ukraine to press the issue by May 9.

This post has been updated.