As the world wakes up to the political storm unfolding in the U.S. around some of Donald Trump's closest former associates, questions are being asked whether the president could now be impeached — although that scenario appears unlikely. The political firestorm reached new heights Tuesday with Trump's former campaign chief, Paul Manafort, and his former lawyer Michael Cohen appearing in separate courts. Manafort was convicted by a jury and Cohen pleaded guilty to separate felony charges. "Together, what these things are going do is that they're going to fuel talk of impeachment," Peter Trubowitz, head of international relations at the London School of Economics, told CNBC on Wednesday, calling it a "double whammy" of the Manafort and Cohen outcomes. "Mr. Trump had a pretty bad day yesterday, and it's really hard to know what's worse here, the indictment of his former election campaign chairman Paul Manafort, or the plea bargain by Michael Cohen, the president's former personal lawyer for violating campaign finance laws," Trubowitz told CNBC's "Squawk Box Europe."

President Donald Trump waves from his vehicle as he prepares to depart for Dubuque, Iowa, from Joint Base Andrews in Maryland, July 26, 2018. Joshua Roberts | Reuters

In New York on Tuesday, Cohen pleaded guilty in a federal court to eight felony counts of tax fraud, bank fraud and campaign finance violations. Potentially the most damaging counts that Cohen pleaded guilty to appeared to implicate Trump directly when he admitted to making payments to two women at the direction of an unidentified candidate for political office, who appeared to be the president. Those payments, Cohen said, were made to influence the outcome of the election. Separately on Tuesday, a jury found Manafort guilty of eight felonies unrelated to the 2016 election: five counts of felony tax fraud, one count of failing to report a foreign bank account and two counts of bank fraud. Manafort's conviction was for charges unrelated to the 2016 campaign. Reacting to the news as he arrived at a campaign rally at West Virginia on Tuesday, Trump expressed sympathy for both of his former aides, saying "I feel badly for both. I must tell you that Paul Manafort is a good man," according to a White House transcript. Trump yet again called special counsel Robert Mueller's ongoing investigation into Russian interference in the 2016 election a "witch hunt." Trump and the Kremlin deny allegations of collusion to influence the 2016 election outcome. Nonetheless, Trubowitz said the developments represented a victory for Mueller. "It's going to make it harder for Republicans in Congress to call for an end to his investigation. He's (Mueller) now got something he can show for his efforts," Trubowitz said. "The second (trial), the plea bargain (by Michael Cohen), makes it harder — even though Mr. Trump was doing this yesterday in West Virginia — for him to insist that this is all a witch hunt, because Cohen pleaded guilty to charges stemming from a grand jury investigation led by the U.S. attorney's office and southern district of New York, i.e. not from Mr. Mueller," Trubowitz added. The White House did not immediately respond when CNBC requested comment on this story.

Impeachment?

With Cohen facing up to five years in prison, questions are being raised as to whether Trump could also be prosecuted. Cohen's lawyer Lanny Davis said Tuesday after the proceedings, "If those payments (of hush money) were a crime for Michael Cohen, then why wouldn't they be a crime for Donald Trump?" Despite impeachment talk, it's no easy task to remove a president in such a way. Presidents Bill Clinton and Andrew Johnson were impeached, but both were acquitted by the Senate. President Richard Nixon resigned before a likely impeachment. There are three impeachable offenses: treason, bribery and the more opaque "high crimes and misdemeanors," but the House of Representatives has the responsibility to accuse the president of one of those things. If a majority in the House agrees, a president is then impeached. The Senate then votes on impeachment, which under the U.S. Constitution requires a two-thirds majority. In Trump's case, starting the impeachment process would require a mass revolt by Republicans against him in the GOP-controlled House, an event even less likely than normal with midterm elections coming in November. Even Democrats are mostly keeping quiet about impeachment to avoid motivating the Republican base before the elections. Public opinion polls have also shown a general unease among the American public when asked if they would like to see Trump impeached should the Democrats win control of the House.

Michael Cohen, former personal lawyer to U.S. President Donald Trump, exits from federal court in New York, U.S., on Tuesday, Aug. 21, 2018. Mark Kauzlarich | Bloomberg | Getty Images

Jacob Parakilas, the deputy head of the U.S. and Americas program at the think tank Chatham House in London, told CNBC that the political implications of the Manafort and Cohen proceedings were not clear cut. "It's fair to say that any day that sees close associates of the sitting president convicted and pleading guilty to numerous crimes … is not a great day for the Republican Party. Yet that said, the (midterms) are still a few months away, and the news cycle these days is so incredibly rapid that if these things don't develop further, it's possible they'll be consumed into a bigger narrative that may or may not favor the Democrats," he said. "But I don't think this is the last we're hearing of either Manafort or Cohen, I don't think this is the end of their sagas."

Richard Johnson, a professor in U.S. politics at Lancaster University, also remarked that he would "urge caution to those who think impeachment is around the corner." "Impeachment is a political process. The jury is 100 U.S. senators, whose overwhelming concern is re-election and, even more pertinently for some, re-nomination. Two-thirds of them must vote to convict. We're in a new partisan landscape from the 1970s. Even if Democrats take control of the House, will there be around 17 Republican senators willing to vote with around 50 Democrats to convict a Republican president? I doubt it," he said in a research note.

Market reaction

U.S. stock index futures were in the red ahead of Wednesday's open but the political fallout from the Manafort and Cohen cases is also being weighed with Sino-U.S. trade talks starting Wednesday. Paul Donovan, a global economist and managing director at UBS Wealth Management, said in a note Wednesday that "President Trump faces either double trouble (Cohen and Manafort) or a witch hunt, depending on your perspective." "Does this matter for markets? It might matter if the president's political capital with Congress was undermined, affecting policy. However, the president does not have that much political capital with Congress and is not asking Congress to pass laws they do not want to pass," he said.