Colin Powell: The moderate military voice sidelined by Bush
White House  The first black man to head the US military, Powell
served under three Republican presidents before switching sides
After serving three Republican presidents, Colin Powell has
given the 2008 Democratic presidential candidate, Barack Obama,
one of his biggest endorsements. Powell's popularity both at
home and abroad means this is a huge blow for Obama's Republican
rival, John McCain.  The 71-year-old served as Ronald Regan's
national security adviser between 1987 and 1989, supporting the
"Star Wars" missile programme, and has long been one of the most
respected African-Americans in US public life.  Under the tenure
of George HW Bush he was promoted to four-star general and
became chairman of the joint chiefs of staff, America's highest
military job. He was the first African-American to hold the
post. Along with General Norman Schwarzkopf, he led the
coalition to victory in the first Gulf war against Iraq in 1991,
becoming a national hero