"Let's play grown-up." When I was a child, that's what we said when we ran out of things to do like playing potsie or throwing rocks in the vacant lot. You'd go in and take your father's hat and your mother's purse and walk around saying, "Would you like tea?" In retrospect we weren't imitating our parents but parents on TV, who wore pearls and suits. But the point is we amused ourselves trying to be little adults. And that's what the GOP should do right now: play grown-up. The Democrats in the White House have been doing it since...