As they charge through the eventful first 100 days, President Obama and his allies are racking up legislative victories. Soon they will have to win the votes of a new audience: men and women in black robes. As the former constitutional-law professor surely knows, that can be a tough crowd. Here’s the core constitutional fact: a progressive president and Congress now face a conservative judiciary, for the first time since 1937. Obama’s ambitious agenda, if enacted, must go before federal courts