An all-time great President? Tricky. Uhh... broker a lasting peace in the Middle East? That'd be worthy of major props. I would also accept getting Congress to cooperate on increased taxes, reduced spending, and a general buckling-down in preparation for years of paying off our debts. Which is probably more likely, but still a 'fat chance' kind of thing.
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I don't like this duchy. Now, it's an adventurer.