So... I actually made a mistake. I was still Portugal's vassal/satellite when I switched over.
Anyway, I cozied up with the French and...
Finally, I get an event that the liberals are done supporting the crown in Portugal so we sent an ultamium. Of course, Portugal rejected our independence.
I reached out to the Americans for an alliance, but they didn't want to be dragged into my affairs. The UK is friends wtih Portugal, so they wouldn't join my side of the war (I am scared they'll come to Portugal's aid).
The French though... The French decided to back me in my war for Independence. (^_^)