Even if President 0bama ran on this as his agenda item, it doesn't mean that Congress needs to “roll over” and not exercise their Constitutional power, any more than the Supreme Court should say “Well the law is Unconstitutional, but he ran on that as his issue and won, so we will let it go.”
Moreover the Presidential power defined by the Constitution is not distributed on a “sliding scale” of electoral support, the myth of the “mandate”; neither is the power situation depending upon its conformance to campaign rhetoric.
“I won” is a dumb argument.
“You didn't win running on THAT” accepts the premise of the dumb argument.
Good point, but he really didn't win running on anything other than a vague and ever-morphing "change."
When he got tripped on the details -- whether past associations, questionable political contributions, his abortion stand in the Illinois senate or other issues that contradicted the official vagueness -- he fought back by labeling the charges "distractions," and "smears."
He's doing basically the same now, wanting no discussion of details, labeling his opponents as obstructionists, and couching his argument in generalities and fear-mongering.