Vice President Dick Cheney is expected to retire within a year. Senior GOP sources envision the retirement of Mr. Cheney in 2007, months after the congressional elections. The sources said Mr. Cheney would be persuaded to step down as he becomes an increasing political liability to President Bush. The sources reported a growing rift between the president and vice president as well as their staffs. They cited Mr. Cheney's failure to immediately tell the president of the accidental shooting of the vice president's hunting colleague earlier this month. The White House didn't learn of the incident until 18 hours later.