How so? I'm always left scratching my head as to why folks don't think a contemporary figure could possibly outshine Washington, Jefferson, Lincoln, et al
That's the piety that keeps us from tearing up the Constitution every generation and replacing it with something worse, as they do in some countries. It's worked pretty well for America, and on the whole it's a good thing.
Sometimes we overdo it, though. A history of the early years of the country will show corruption, manipulation, and political hysteria. I guess it's possible that a leader like Reagan could outshine the founders.
But A) whatever their difficulties with practical politics the founders were better educated in political philosophy and deeper political thinkers than any politician is likely to be today. Right now politicians outsource their thinking, as they delegate their speechwriting. Reagan was to some extent an exception, but once he took office the time he could devote to theory was limited.
The founders could be creative and come up with good ideas. They came first. Today, original "new ideas" are very often bad ones. I doubt we really want modern intellectuals trying to "refound" the country or rewrite the Constitution.
And B) Washington really was an exception. No politician today is likely to have done and sacrificed so much for his country as Washington did. Great challenges make great leaders and no President today is likely to face trials as harrowing as Washington did in the Revolution. To mention Valley Forge ought to be enough.
Washington kept the country a republic, rather than a monarchy or a military dictatorship. And he stood apart from all the political manouevering and struggles for power. Adams and Jefferson, Hamilton and Madison look smaller because of their partisan tricks and passions. Washington remains above all that and committed to the nation, rather than to one party or another.
It's true that there's something romanticized about the way countries look back on their founders. Those days are always made out to be epic or heroic ages. But they did face great trials in those days. Setting up a country on the right foundation is a difficult thing. Look at how many new countries around the world have failed, and you can see how great an achievement our founding was.
It's certainly possible that a leader today might be quite great (though contemporary politics does tend to discriminate against those who have such glimmerings of greatness in them), but we won't really be able to measure their greatness until after their gone. The past is largely dead and we can see it in context. Living figures can still screw up something awful. The older generation of Britons can take pride in Winston Churchill, but in 1940 or 1930 or 1920 it wasn't at all clear what history would make of him.