Obama is pushing Congress to pass a bill before January 2014, after that date, the Senate controlled by the GOP can pass a bill which he will surely veto...
He doesn't want to become the POTUS of "NO"
He knows it will never pass before then unless the GOP capitulate to the Democrat controlled Senate demands...
He's goading them into action...
The majority of the Senators who voted for Obamacare are no longer Senators.