The accusations of financial crimes against President Bill Clinton surrounding the Whitewater real estate development faded and were replaced by claims of perjury and obstruction during the investigation surrounding his extramarital affair.
So to the quest to find Trump-Russia collusion will fade and will be replaced by the pursuit of conspiracy, money laundering and other financial crimes relating to the payoff of women alleging affairs with Trump.
The Cohen matter has put the President in the direct vicinity of a host of possible crimes.
For starters, Cohen's allegation that the President directed him to pay the hush money could be a violation of campaign-finance laws, not to mention a tax-fraud case depending on how Cohen was reimbursed and how the payments were recorded. (And charges of tax fraud are often accompanied by related charges such as wire fraud.)
These allegations could be proved with statements and records provided by Cohen. No prosecutor would have to interview the president.
It would not lead to an indictment of a sitting president, but I think it could lead to impeachment.
The prospect of impeachment does make things different, but as Clinton showed, it doesn't have to be politically fatal.
Another worrying fact for Trump supporters is that what we know about Cohen is bad, but in this environment, there are almost always some surprise revelations.
Think of Cohen as the tip of the iceberg: We aren't sure what else is down there, but we know there is something.
It will be of little comfort to Republicans that they can rail about the fact that there was no collusion - that's just a moral victory.
The world is about to move on from collusion and toward conspiracy and financial crimes associated with the President's dealings with Cohen.
The arguments the GOP could use are that these are minor violations in that they are related to tangential campaign-finance laws or essentially victimless crimes of improper reporting of money transfer, or laundering.
But they certainly rise to the level of high crimes and misdemeanours that the Democrats and perhaps some Republicans would accept as justification for impeachment.
So yes, this time around things are different. Yesterday's developments may not be fatal, but they don't look good and they certainly weaken the Trump presidency.
In the meantime, Republicans everywhere are more on the defensive than ever. Voters and local media will demand that every GOP politician explain his or her positions and justify his or her continued support of the President.
And this hurts what should be a good political environment for Republicans. I always say there is no such thing as a political problem that isn't solved by 4 per cent GDP growth.
Well, that theory may be about to be put to the test. A humming economy is good, but will it be enough to distract and placate voters who are demoralised and frightened about what they see as the state of American political leadership?
And finally, remember an important rule of the swamp: Bad gets worse.
Today things are pretty bad. By the Sunday talk shows, they will be a lot worse.
Prosecutors in New York and Washington are just getting started. There is a lot more to come.
- Ed Rogers is a veteran of the Ronald Reagan and George H.W. Bush White Houses
