Given all this, let's pin down exactly what we know — and what is alleged — about Manafort's ties to Ukraine.
The basics: Manafort was a Republican political consultant who came to prominence in the 1970s. He worked for Gerald Ford, Ronald Reagan and George H.W. Bush, but afterward he faded from view.
How he got started in Ukraine: In 2005, Manafort got a job advising a Ukrainian steel magnate, one of the richest men in that country, on how to improve his business empire's public image. The job helped revive Manafort's political career and shore up his struggling finances, The Post reports.
And here's where Manafort's ties to pro-Russian politics really begins: His billionaire client was a supporter of Viktor Yanukovych, the prime minister of Ukraine and an ally of Russian President Vladimir Putin.
Yanukovych, too, had an image problem. He had just lost a nasty presidential election fight that was fraught with allegations of fraud, the poisoning of the pro-Western opposition leader, a court ruling invalidating Yanukovych's win, and widespread, violent protests that became known as the Orange Revolution.
Yanukovych had relied on Russian advisers for that disastrous election, and decided to turn to an American for a makeover (though PolitiFact reports that Manafort had actually unofficially counseled Yanukovych during that 2004 election).
Manafort officially worked as a political consultant for Ukraine's ruling party from circa 2006-07 to 2012.
What he actually did in Ukraine: The Times reports that Manafort soon became a "significant" influence in the country beyond helping make over a politician and his party. Manafort persuaded the Ukrainian government to change its grain policies in a way that benefited a U.S. agribusiness giant, and to consider deals with Exxon and Chevron for oil exploration. He also got involved in some lucrative side deals with Russian and Ukrainian oligarchs, but many of them fizzled, and some of the actors he worked with are under scrutiny by U.S. investigators.
But his main job was politics. And The Post reports that Manafort tried to crack the whip with the Ukrainian politicians he was counseling:
Manafort and half a dozen businessmen, lawyers and political analysts involved in Ukraine at the time brought discipline and focus that the Yanukovych-led campaigns had lacked.
He got Yanukovych to comb his hair better, to stay on message during public appearances. ... He drilled them on talking points and told them what suits to wear.
“He tried to control everything,” [a former member of Yanukovych's party] recalled. “How people who represented the party would be dressed, the words they said, their makeup and the stylists. Every small detail.”
Yanukovych won election in 2010 but fled to Russia in 2014 amid protests and riots over his decision not to sign a trade pact with the European Union, a decision many in the country saw as influenced by Russia.
Even with Yanukovych out of the country, the Times reports Manafort kept working in Ukraine with the president's former chief of staff to help keep the pro-Russian party in the political game. It worked. The party ended up being a significant influence in parliament.
New revelations about Manafort's Ukraine work: Manafort's involvement in Ukraine grabbed national attention after the New York Times reported Monday his name is listed on secret ledgers in the country as being owed $12.7 million in undisclosed cash payments from Yanukovych's party.
The handwritten ledgers were uncovered by Ukraine's newly formed anti-corruption bureau, the Times reported. Investigators told the reporters this is part of a broader illegal off-the-books payment system involving many Ukrainian politicians and officials with ties to Yanukovych. The Post reports investigators are trying to determine whether Yanukovych and his allies stole up to $100 billion before Yanukovych fled to Russia.
But investigators said they were still trying to determine whether any money actually exchanged hands. Manafort has strongly denied he received "a single off-the-books cash payment."
"The suggestion that I accepted cash payments is unfounded, silly and nonsensical," Manafort said Wednesday in a statement, adding he didn't work with the official Ukrainian government.
On Thursday, Ukrainian investigators released line-item entries to try to prove their allegations. What they show appear to bolster an Associated Press report that Yanukovych's party spent a lot of money in the United States to try to influence its image here.
And Manafort may have been involved in that.
Manafort's ties to Ukraine's lobbying in the U.S.: The Associated Press reported this week that while Manafort was working in Ukraine, his lobbying firm secretly tried to influence the U.S. press and government officials, apparently on behalf of the Ukrainian Embassy, which didn't want its fingerprints on any of this.
The lobbying included attempts to gain positive press coverage of Ukrainian officials in the New York Times, The Wall Street Journal and the Associated Press. Another goal: undercutting American public sympathy for the imprisoned rival of Ukraine's then-president. At the time, European and American leaders were pressuring Ukraine to free her.
The AP also reported that Manafort helped the pro-Russian Ukrainian party funnel some $2.2 million to two prominent Washington lobbying firms in 2012.
The goal, AP reported, was to have these firms advocate for the pro-Russian Ukrainian government — but, again, to do it in a way that hid Yanukovych's involvement in all this.
It's not uncommon for political consultants to work overseas, but if you are paid directly by a foreign government, you have to let the U.S. government know.
In a weird political twist, AP reported Manafort hired two lobbying firms for this job, each with its own ties to presidential candidates past and present.
One of those was the Podesta Group. The founder is Tony Podesta, whose brother, John Podesta, chairs Hillary Clinton's campaign. The other lobbying group has ties to Mitt Romney. Both firms told the AP they didn't think they needed to tell the Justice Department what they were doing.
And that's what we know so far about Manafort's complicated relationship with pro-Russian actors in Ukraine.