Trump was right to be panicked back in April, and since then we've all learned of more damaging facts that Cohen may substantiate. Cohen is at the intersection of at least three possibly disastrous legal stories.
1) Cohen allegedly was involved in the payment of hush money to silence multiple women with whom Trump allegedly had extra-marital affairs.
The political fallout will depend on how many women and the circumstances of those payments. The criminal liability here concerns violation of campaign-finance rules as part of a deliberate attempt to conceal large amounts of money from voters. Blaming Cohen exclusively will be hard for Trump to pull off, given the tape we already have heard. If there is other evidence documenting Trump's involvement, his legal problem worsens.
2) Cohen has been Trump's "fixer" and dealmaker for years.
He was at the centre of the failed Trump Tower project in Russia and likely would have been privy to other Russia-related transactions, if any, over years. Trump has insisted the Special Counsel not go into his personal finances. The chances that Robert Mueller and his team are doing just that and will continue digging with Cohen as a guide has gone up dramatically.
3) Cohen may have plenty of other information relating to Trump campaign contacts with Russia and to Trump's own efforts to conceal them and disable the investigation.
Goodness knows what recordings, documents and firsthand recollections he may have. What, for example, does he know about the Trump Tower meeting in June 2016? What, if anything, does he know about contacts that members of the Trump team had with Russia during the campaign and/or the transition? Given that the White House counsel Donald McGahn, who is not Trump's personal lawyer, has spent 30 hours or more with the Special Counsel, it is not as if Cohen would be the only witness to possible impropriety. Cohen and McGahn may bolster one another's accounts.
Cohen matters because he may have critical information relating to all three of these evolving stories.
Moreover, he cannot be written off as someone peripherally related to Trump.
He cannot be written off as a coffee boy or as someone who went in and out of Trump's orbit in a matter of weeks.
In short, Cohen's plea is a crushing blow because he is the first cooperating witness that could implicate Trump directly in all three matters - the women and campaign money, Trump's business dealings, and the Trump campaign's Russia connections.
Buckle up. Trump now goes from the frying pan into the fire.