Is Obama ready to be chief?

clipped from www.msnbc.msn.com Back in January, I argued that the outcome of the Democratic nomination hinged on one question: To what extent can Barack Obama reassure primary and caucus voters that he is ready to be their president? Now, nearly five months later, the answer may determine the outcome of the general election.   Obama heads to Europe, Mideast July 17: Presidential hopeful Barack Obama is heading on a five-country European and Middle East tour. NBC’s chief White House correspondent, David Gregory, reports.