IN a tradition that stems from the days before air conditioning came to August, the highest elected officials in town are deserting the premises.Secretary of State James Baker III, after 23 straight days of traveling diplomacy, is monitoring the Middle East peace process from his ranch in Wyoming. For President Bush, who left for his beloved Walker's Point in Kennebunkport, Maine, on Tuesday, vacation this year is no laughing matter. His determination, in fact, is nearly grim. "I think I've earned it," he asserted to reporters last Friday. "Like a lot of Americans," he quickly added, for the president is not one to boast or imply that Americans are not all as indefatigable and deserving as he is. "And I'm looking forward to it." And then, in case anyone on his staff or attention-craving interest group might detect any weakness of will, any opening for more work in his Walker's Point schedule, he added a stern word: "And it will not be denied." "There are a number of people pushing for an occasional trip or two," said White House press secretary Marlin Fitzwater on Monday, "but I think the president is resisting ... mightily." Mr. Bush will be in Maine four weeks, his longest vacation yet as president. Last year, he was all but robbed of his traditional respite by the predations of Saddam Hussein, who invaded Kuwait just before Bush left for Kennebunkport. Although the vacation officially stayed on - pointedly proving that the president was no prisoner to the crisis - he was in fact working assiduously to put together an international front against Iraq. The only summer in his life he actually missed spending in Kennebunkport altogether was in 1944, as a Navy pilot on combat duty in the Pacific. Bush may unwind but, if the past is any guide, he may not slow down. His golf game is played against a stopwatch at breakneck speed. He fishes from his twin-engine cigarette boat, out-running the Secret Service boats around him as he roars to a new fishing spot. But he is also likely to be surrounded by more grandchildren than policy briefers. Work will certainly intrude. But he has held his plans to a quick trip to Pittsburgh next Wednesday to speak to the Fraternal Order of Police, a teleconference call to the National Governors' Association as they meet in Seattle Aug. 24, and hosting British Prime Minister John Major for a couple of days at the end of August. Bush was widely expected to use his vacation this year to meet with his top political strategists and begin framing his campaign for reelection. This may have been what the top political strategists had in mind, not the president. He met with them instead at Camp David over the weekend and listened to their recommendations about how the campaign should be structured and financed and when it should start. According to Mr. Fitzwater, Bush just listened and made no decisions and gave no instructions. The business of politics and policy does not stop for vacations, of course. White House staffers will remain on the job to monitor the progress of the Clarence Thomas nomination to the Supreme Court, ready to counter any opposition that might mount while Congress is in recess. The White House will launch at least two other policy initiatives during the next few days. One concerns how the administration plans to keep the Bush campaign pledge of "no net loss of wetlands." The other concerns cutting the cost of civil litigation. Congress will be checking the home-district opinion barometers this month on matters such as Mr. Thomas's confirmation, a nickel-a-gallon gas tax, abortion counseling at federally funded clinics, and extending unemployment benefits. But hear Fitzwater's plea on his way out of town with Bush on Tuesday: "Don't actually force me to focus on issues ... I'm out of here."