Kermit the Frog and Miss Piggy? I'd say they would be better candidates to play the roles of Hillary Clinton and Bernie Sanders. You have the dominant one who always gets their way in the end(Clinton) versus Kermit the Frog(Bernie Sanders) who is the mellow voiced one who always gets overruled in the end by Miss Piggy.
If we are going along with the Sesame Street line of thought, I'd say Oscar the Grouch would be the best one of all of them to play Donald Trump. He always comes off as negative all the time which is perfect for Trump who often does the same thing himself.