Laura Bush delivered a lot of jokes during her now-famous stand-up routine at the White House Correspondents' Dinner, but one of them touched a real sore spot. Not the joke about milking the horse. This one: "I said to him the other day, 'George, if you really want to end tyranny in the world, you're going to have to stay up later.'" When the joke was replayed over and over again on TV, a cry rose up from every corner of this sweet and verdant land: "No, no, George, don't stay up later! You just go on to bed! You're doing too much already! Really!"

Or maybe that was just me. In any case, Mrs. Bush's joke points to something important in our present political moment, four very busy months into her husband's very busy second term. It even sheds light on those discouraging poll numbers that have lately troubled all the president's men and his publicists in the press. The president himself, of course, pays no attention to polls.

And a good thing, too, because Bush's job approval ratings are now at the lowest point of his time in office-down to 47 percent in the latest Washington Post poll, 48 percent in USA Today's. In the Post poll, the number of people who "strongly approve" of his job performance, which for most of the last four years has roughly matched the percentage of people who "strongly disapprove," has fallen to 25 percent, while the strong disapprovers have surged to 38 percent.

A solid majority, 56 percent, approve of Bush's handling of the "U.S. campaign against terrorism." From there, the numbers head south. Only 42 percent approve the way Bush has conducted the Iraq war, and 54 percent now say they believe the war should never have been fought. Forty percent approve his handling of the economy. With gas prices high, approval of Bush's energy policy is low: 35 percent. Even lower, though, is the percentage approving Bush's signature domestic initiative: 31 percent approve, and 64 percent disapprove, of the president's handling of Social Security.

These gloomy data follow the Terri Schiavo affair, when very large majorities--up to 70 percent in some polls--expressed their distaste for the effort by Bush and congressional Republicans to encourage federal courts to take up her case.

Scanning the poll numbers, Dean David Broder of the Washington Post announced that Bush is the victim of "overreach." John Podhoretz, in the New York Post, came up with a better tag and got closer to the nub. The public, he wrote, may be suffering from "Issue Fatigue"--an overload of public policy proposals and the politicking that goes with them. "While [Bush] refused to allow himself to rest after the 2004 election," Podhoretz wrote, "the American people seem to have desperately wanted a break." Both Podhoretz and the Dean are on to something, but what if they don't go far enough? Bush's problem may be more elemental. Overreach, and the resulting fatigue of the public, may be the inevitable consequences of the way Bush approaches his job--it might, in other words, be built into his governing philosophy.