WASHINGTON – President Barack Obama and his family are heading off Friday for the weekend to a spectacular national park on the coast of Maine, no doubt hoping this latest jaunt doesn't fall victim to the Obama family travel hex. That would be the one in which events seem to scramble the plans whenever Obama has his wife and daughters in the mix. In a mere 18 months on the job, Obama has rolled up an impressive record of diversions, interruptions, delays and outright cancellations of planned family travel — all thanks to the nonstop demands of a turbulent...