The president departed Tuesday for his longest stretch yet away from the White House, arriving at his Crawford ranch in the evening for a stretch of clearing brush, visiting with family and friends, and tending to some outside-the-Beltway politics. By historical standards, it is the longest presidential retreat in at least 36 years.

The August getaway is Bush's 49th trip to his cherished ranch since taking office and the 319th day that Bush has spent, entirely or partially, in Crawford -- nearly 20 percent of his presidency to date, according to Mark Knoller, a CBS Radio reporter known for keeping better records of the president's travel than the White House itself. Weekends and holidays at Camp David or at his parents' compound in Kennebunkport, Maine, bump up the proportion of Bush's time away from Washington even further.

Bush's long vacations are more than a curiosity: They play into diametrically opposite arguments about this leadership style. To critics and late-night comics, they symbolize a lackadaisical approach to the world's most important day job, an impression bolstered by Bush's two-hour midday exercise sessions and his disinclination to work nights or weekends. The more vociferous among Bush's foes have noted that he spent a month at the ranch shortly before the Sept. 11, 2001, attacks, when critics assert he should have been more attentive to warning signs.

To Bush and his advisers, that criticism fundamentally misunderstands his Texas sojourns. Those who think he does not remain in command, aides say, do not understand the modern presidency or Bush's own work habits. At the ranch, White House officials say, Bush continues to receive daily national security briefings, sign documents, hold teleconferences with aides and military commanders, and even meet with foreign leaders. And from the president's point of view, the long Texas stints are the best way to clear his mind and reconnect with everyday America.

"I'm looking forward to getting down there and just kind of settling in," Bush told reporters from Texas newspapers during a roundtable interview at the White House on Monday. "I'll be doing a lot of work. On the other hand, I'll also be kind of making sure my Texas roots run deep."

"Spending time outside of Washington always gives the president a fresh perspective of what's on the minds of the American people," White House press secretary Scott McClellan told reporters Friday. "It's a time, really, for him to shed the coat and tie and meet with folks out in the heartland and hear what's on their minds."

Just as Bush has made these August trips a regular feature of his presidency, so, too, have Democrats made a tradition of needling him about them. This year, opposition politicians are tying his departure from Washington to the CIA leak case that has swept up his top adviser, Karl Rove.

"The White House stonewalling operation is moving to Crawford for the dog days of summer, but they can't hide from the legitimate questions dogging the president and his refusal to keep his promise and fire Karl Rove," said Josh Earnest, a spokesman for the Democratic National Committee.

Presidents have often sought refuge from the pressures of Washington and from life in the White House, which Harry S. Truman called the crown jewel of the American prison system. Richard M. Nixon favored Key Biscayne, Fla. Bush's father preferred Maine. Bill Clinton, lacking a home of his own, borrowed a house on Martha's Vineyard, except for two years when political adviser Dick Morris nudged him into going to Jackson, Wyo., before his reelection because it polled better.

Until now, probably no modern president was a more famous vacationer than Ronald Reagan, who loved spending time at his ranch in Santa Barbara, Calif. According to an Associated Press count, Reagan spent all or part of 335 days in Santa Barbara over his eight-year presidency -- a total that Bush will surpass this month in Crawford with 3 1/2 years left in his second term.

"The Oval Office is wherever the president of the United States is," said Kenneth M. Duberstein, who was Reagan's last White House chief of staff. "With the communications being what they are, the president can communicate instantly with whomever he wants anywhere in the world."

Bush will not return to the White House until after Labor Day, but his staff has peppered his schedule with events to dispel any impression that he is not on duty. He will visit at least seven states, mostly with quick day trips, including New Mexico, where he plans to sign energy legislation into law. He gets off to a quick start this week, with a speech Wednesday in nearby Grapevine, Tex., then he plays host to President Alvaro Uribe of Colombia at the ranch Thursday. His schedule is clear Friday through Sunday.

At some point, Bush told reporters Monday, Secretary of State Condoleezza Rice and Defense Secretary Donald H. Rumsfeld will visit for consultations. "I have a busy couple of weeks down there," Bush said.

But he will make time for fun, or at least his idea of it. Bush rarely takes the type of vacation one would consider exotic -- or, to some, even appealing. His notion of relaxation is chopping cedar on his ranch or mountain biking through rough terrain, all in 100-degree-plus temperatures in dusty Texas where crickets are known to roast on the summer pavement. He seems to relish the idea of exposing aides and reporters to the hothouse environment.

"I just checked in with the house -- it's about 100 degrees," he told reporters Monday. "But no matter how hot it gets, I enjoy spending time in Texas."