The play, which won the Pulitzer Prize in April, has also swept many of the pre-Tony awards, and is well liked by many mainstream voters.
The challengers to both presidents were undermined by the rise of noisy extremists in their respective parties who alarmed many mainstream voters.
If General Powell tips too far to the right on questions like slowing the growth of Medicare spending, this argument goes, he alienates mainstream voters.
Strong opponents of abortion, for example, may react positively to certain religious allusions that appear innocuous to mainstream voters.
"If the referendum had been placed in a regular election," Mr. Caton said, "mainstream voters would have been there to vote the measure off the books."
It could be even more damaging to Mr. Clinton, who has embarked on an effort to show mainstream voters that he can deliver on a promise.
"And if it keeps on lurching, it's going to leave the bulk of voters who are moderate, mainstream voters uncomfortable with their agenda."
The candidate who comes out of here the winner will have found his presidential footing among mainstream voters.