What does that mean? Words take on meaning from the context in which they are spoken.
Today it was spoken in the context of taking care of little children. Of denying them care or stopping their suffering.
Bush II refused, twice, to sign the bill President Obama signed today. The bill was not perfect as far as Bush II was concerned, and thus his demand of perfection was the enemy of the essential care some 8 million American children need.
Instead, his war in Iraq was more perfect in his analysis, and therefore required more attention and much, much more money than the suffering children here at home.
Thus, Bush II's perfect war was the enemy of the children's essential needs.
Which led to the perfect political storm we now call the '08 elections. A storm that blew the republican presidency away, blew control of the House further away from the republicans, and blew control of the Senate further away from the republicans.
Undaunted, the republicans still seek a perfect bill, while the nation's economy cries out for essential stimulus. As it turns out, we have "progressed" toward economic death these past 8 years, and now we need some essentials to stop the "progress". So please don't demand perfection now.
Demanding perfection should never send any one person or any nation to the hell of depression. Depression a la 1934 according to England's Gordon Brown.
Yes, President Obama was spot on, all too often in republican political gamesmanship, perfection is the enemy of the essential.