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1.
Assigning blame to President Obama] regardless of the context. Reducing every discussion to a debate on whether Obama is good or evil. Relating everything back to whether or not Obama is a good President.
Did you hear about that guy that was killed by the plane coming in for a crash landing? I bet if Obama hadn't changed all the FAA] laws it never would have happened.

Dude. Stop hating]..enough with the Reductio ad Obamaum. Not everything that happens is related to your dislike of Obama.
by radiantmercury March 17, 2010
 
2.
When a conservative or tea-bagger uses these labels or name calling: Marxist, socialist, communist in a discussion, attempting to discredit or one-up the dialog.

(Note: The mannerism stems from the culture of parroting conservative entertainers: Beck, Hannity, Limbaugh, etc.)
John, "What have conservatives done to create, allow, or support affordable health care for ALL Americans?"

Bubba, "We don't need your socialist marxism!"

John, "Why do you think civil society is socialist?"

Bubba, "Big government = communism"

The mannerism is part of the hatred for Obama, hence the term: "Reductio ad Obamaum"
by Bob_yer_uncle June 19, 2011