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.

But after his inauguration, Obama apparently grasped two realities. The first: Antiwar rhetoric on the stump was easy, but the responsibility of keeping Americans safe from terrorism and Islamic radicalism was not. The second: He guessed that liberal furor over the war on terror and the interventions in Iraq and Afghanistan had always been mostly about opposing George Bush — not really principled opposition to actual wartime policies.

So after early 2009 there was no more talk of a lost war in Iraq, and no more deadlines to bring home our 130,000 troops that are still there. The Bush-Petraeus plan of staged withdrawal instead still operates. There has been a marked escalation in Afghanistan.

Guantanamo Bay is still open 15 months after the inauguration — and three months after its promised closure date. There have been more Predator drone assassinations during the early months of the Obama administration than in eight years of the Bush tenure. Renditions, tribunals, intercepts and wiretaps go on as before, or have been expanded.

And as Obama must have anticipated, there are now no more antiwar rallies and Hollywood movies, or anguished op-eds about either an imperial warmongering America or a virtual police state at home. A raging Michael Moore and Cindy Sheehan are distant memories. We once read that Bush as a wartime president frivolously played too much golf; we don't read that Obama has played more golf in one year than Bush did in eight.

Progressives have concluded that to now oppose the Bush-Obama foreign policies would only hurt their own party's domestic agenda, and that a cool, sensitive President Obama does what he must reluctantly — in contrast to a zealot warmonger like former President Bush.

Call all this hypocrisy, but it does create interesting political irony. Conservatives don't know whether to score points against Obama for his about-face and past politicizing of national security issues, or praise him for continuing what they feel were necessary Bush efforts that have kept us safe.

Liberals may be slightly embarrassed that their past furor over the various ongoing wars on terror more or less mysteriously ceased in January 2009. And they are certainly angry that conservatives are opposing Obama's domestic agenda in as coarse a fashion as they themselves once did Bush's foreign policy.

How does this affect America at large? Liberal Nobel laureates can fight wars abroad pretty much as they deem necessary — without worrying that they are going to be vilified at home.

Texas cowboys cannot.