In late September of 1908, the New York Giants and the Chicago Cubs were tied for first place in the National League pennant race with about a week to go in the season. (This was in the days when there were no divisional playoffs, let alone wild cards. If you won the regular season title, you went to the World Series.) The two teams met for a game at the Polo Grounds and went to the bottom of the ninth tied 1-1.
With two outs and Moose McCormick on first, Giants first baseman Fred Merkle singled to right field, sending McCormick to third. The next batter then lined a single up the middle, scoring McCormick with what should have been the winning run and putting New York into first. But there was a catch. Merkle, who was digging hard for second base, swerved away (he never touched second) and started running for the Giants' locker room in center field as soon as he saw McCormick touch the plate. As was their wont in those less orderly days, Giants fans immediately came swarming onto the field when their team won, and Merkle wanted to get a head start on the happy mob.
This, then, was what's known in baseball as Merkle's Boner. (Refrain from all vulgar snickers, please.) According to the rules of baseball, the game wasn't actually over until Merkle touched second base. Cubs second baseman Johnny Evers (of Tinkers-to-Evers-to-Chance fame) realized this, tracked down the ball (actually, people who were there say he got another ball from the dugout, since the original ball had disappeared into the crowd), grabbed an umpire, and stepped on second base, which in theory completed a force play on Merkle. After much discussion, the umpires called Merkle out and declared the game a tie that would have to be replayed. A week or so later, it was, and this time the Cubs won, sending themselves to the Series and consigning Merkle to permanent notoriety.
There's no question that according to the rules as written, Merkle did have to touch second base. But according to custom in 1908, runners who were on base when a game-winning run scored in the ninth tended not to touch the next base and instead headed for their clubhouses. A month or so before, in a game against Pittsburgh, Johnny Evers had tried the very same trick against a Pirate runner who had left the field at game's end, but that time the umpire had rejected his appeal.
In suddenly invoking the letter of the law, then, the umpires were requiring Merkle to act in a way that he had no reason to believe he was supposed to act. The community's understanding of the rule that a runner must always touch the base to which he is forced was that this rule didn't apply when a game was won in the ninth inning. What Merkle did, then, was what the community expected him to do. This may not mean he was right to do what he did. But there's an argument to be made that when custom systematically changes the meaning of a law--in this case, changes it by adding an important exception--it's a mistake to invoke the original meaning arbitrarily and without warning.
All of which brings us back to New York City's crackdown last week against people who double-park while their streets are being cleaned. This form of double-parking (which is clearly distinguishable from double-parking in shopping or business districts) is customary throughout the city. On my street, there's a guy who will double-park your car for you and then return it to curbside when the three-hour street-sweeping period is over. It's been understood that double-parking is technically illegal but that this is an orderly and systematic community response to the reality that people need a place to put their cars while the streets are being cleaned.
By descending on selected residential neighborhoods and ticketing all those double-parked cars, the cops have pulled a Johnny Evers. They're just enforcing the law as written. But by doing so without notice, they're catching people breaking rules that the community had, in a sense, decided didn't need to be enforced. (I exaggerate here, since the "community" is the community of car owners.) And insofar as much of our everyday lives depends on knowing that certain rules count and others don't--like laws banning cursing out loud, or spitting in public, or oral sex--Rudy Giuliani is making everyone feel very unsettled.
Actually, though, the unannounced war on double-parking is not really characteristic of Giuliani. Most of his previous Jesuitical initiatives--against jaywalking, speeding, gridlock, and the failure to wear seatbelts, among others--have been announced well in advance, so that notice was served that as of a certain date, things were going to be different. And if you're going to hold people to the letter of the law, that seems like the way to do it, because it'd be hard to have any sympathy for Fred Merkle if before that September game the umpires had told both teams to make sure they touched all the bases in the ninth inning.