— Dave Weigel has the backstory on the Koch-Cato struggle.

— Nate Silver handicaps Super Tuesday. (Spoiler alert: It looks good for Romney.)

— Could global warming end Canada’s ice hockey dominance? Michael Levi is skeptical.

— The mother of a boy dying from Tay-Sachs disease writes a moving essay on the ethics of prenatal testing.

— Jose Andres’s forthcoming food truck, Pepe, will feature a $20 sandwich.