If it’s August, it must be time for that annual Washington political tradition: griping over the president’s vacation. Through wars and natural disasters, recessions and reelections, the getaway locales for America’s chief executive have been dissected by critics looking for symbolic reasons why the president shouldn’t go. With 14 million Americans out of work, a volatile stock market and a historic downgrade of the country’s credit rating, President Obama is set to begin a 10-day retreat Thursday at a 28-acre Martha’s Vineyard compound called Blue Heron Farm, which costs an estimated $50,000 per week to rent.