Krathhammer was once a staffer with Democrat Walter Mondale
Ronald Reagan was once a Democrat. Your point?
This assertion, which ODH has flacked around FR before, is absolute rubbish. Krauthammer criticizes Obama because Obama is a threat to the establishment status quo which Krauthammer cherishes. He does not do it as a conservative.
Charles Krauthammer is a brilliant man. He is a perceptive and insightful analyst on many topics, particularly geopolitical power issues and the threats posed to this country by both enemy nations and non-state actors, e.g. terrorists. He also offers useful insights regarding the power struggles between various traditional establishment blocs such as the Democratic and Republican parties, the Executive versus the Legislative branches, etc..
I read his articles and recommend others do so as well for the many helpful perspectives he offers on those types of topics. I also caution against blind acceptance of him or any other pundit or public figure as a reputable authority.
That said, the one thing Krauthammer is not is a conservative. I've confronted OldDeckHand before on this assertion that Krauthammer is a conservative, and I presented him with the following quote:
"Ultimately, a civilized society must disarm its citizenry if it is to have a modicum of domestic tranquility of the kind enjoyed by sister democracies such as Canada and Britain. Given the frontier history and individualist ideology of the United States, however, this will not come easily. It certainly cannot be done radically. It will probably take one, maybe two generations. It might be 50 years before the United States gets to where Britain is today. Passing a law like the assault weapons ban is a symbolic - purely symbolic - move in that direction. Its only real justification is not to reduce crime but to desensitize the public to the regulation of weapons in preparation for their ultimate confiscation." - Charles Krauthammer, "Disarm the Citizenry," The Washington Post, Friday, April 5, 1996, page A19
Krauthammer has never apologized for nor recanted this position. It is not possible to hold this position and be a conservative. It is not even possible to hold this position and honor an oath to uphold and defend the US Constitution.
I received no response at the time, and he and the other party who were flacking the "Krauthammer is a conservative" meme immediately departed and the thread died.
Again, Krauthammer is no conservative. Calling him a liberal is not quite accurate either. Those labels are simply inadequate. What he is is an elitist authoritarian statist who, by his own words, cares not one whit for the ideas and principles regarding the inalienable rights and freedom of individuals put forth in the Declaration of Independence and codified and guaranteed in the US Constitution.
Krauthammer is indeed brilliant, and he can be useful at times and on certain issues, but he is no friend of the American people, the US Constitution and the Bill of Rights. And, citing him as a conservative authority is nonsense. You might, at times, find him fighting beside you as the enemy of your enemy, but despite that much overused adage, it doesn't make him your friend.