The Washington Post editorial on Pelosi's trip speaks volumes on just how bad a decision this was. This time, she has also apparently given Assad an impression about Israel's position that was nowhere near accurate.
It happened in the 1980s, too. Remember the Dear Commandante letter? Or John Kerry and Tom Harkin visiting Daniel Ortega, and then undermining Ronald Reagan's foreign policy? Pat Leahy leaking stuff all over the place? There is only one person entitled to conduct negotiations on behalf of the US - the President (or those he designates).
Quite frankly, with stuff like Pelosi's trip, we could be in the same situation that we had in the 1980s. Back then, Ollie North was justified in lying to Congress. These days, with Pelosi hobnobbing with Bashir Assad, and other Democrats willing to cover for any thug in the world, including Mahmoud Ahmadinejad, whose country sent forces into Iraqi waters to kidnap 15 military personnel from one of our closest allies. And they wonder why people think they are wimps who can't be trusted to handle national security?
We need to revitalize the Logan Act, and to also make it very clear that all options are on the table. If that means a confrontation with the Democrats, bring it on.