In politics, having power and keeping it often mean fudging a little on ideology.
So conservatives sometimes convince the country to do very liberal things -- think of Richard Nixon going to China, Ronald Reagan granting a blanket amnesty to illegal aliens, or George W. Bush running big deficits.
Liberals can sometimes act like conservatives without worry of being smeared by their base as heartless right-wingers -- remember Bill Clinton's agreement to sign welfare reform and put caps on federal spending.
But in matters of war, being liberal is a great advantage for a president.
The mainstream media and cultural elite give a Democratic commander in chief a pass that would rarely be extended to a Republican. Perhaps this double standard occurs because they believe a progressive president goes to war only reluctantly -- even though most of our bloodiest conflicts have been fought under Democratic presidents.
Woodrow Wilson sent millions of soldiers to Europe and helped to win World War I through head-on clashes with the German army. Yet the country saw him as an idealistic peacemaker. Franklin Roosevelt and Harry Truman, despite respectively firebombing Japan and dropping two atomic bombs, could still count on unified support from the nation's elite.
We equate Vietnam with Richard Nixon, who inherited the war, not John Kennedy, who got us into it in the first place. Few remember that Bill Clinton neither asked Congress nor went to the United Nations before he bombed Serbian strongman Slobodan Milosevic into submission.
Noble laureate Barack Obama is enjoying this traditional exemption from wartime criticism -- and he is using it to good effect.
Candidate Obama, like his rivals in the Democratic presidential primaries, ran on an array of antiwar themes. Iraq was lost; the surge had failed; it was long past time for all combat troops to come home. President Bush had supposedly shredded the Constitution by starting up military tribunals and renditions, and by opening the Guantanamo Bay detention facility. Bush & Co. had also authorized Predator drone assassinations, pushed through the Patriot Act, and expanded wiretaps and intercepts.
Obama's rhetoric reflected the Democratic orthodoxy that by 2006 saw unhappiness with the war as a winning campaign theme.