American voters don’t trust Democrats on national security, for good historical reasons — the U.S. defeat in Vietnam, Jimmy Carter’s surprise at Soviet aggression, the party’s 1980s embrace of the nuclear freeze and its lack of support for the 1991 Persian Gulf War.

President Bush rode a 30-point GOP advantage on national security and fighting terrorism to re-election in 2004, but doubts about his Iraq policy have eroded that lead to the teens.