Obamacare is going to cause a recession? LOL!
There is a difference between something being the cause of a recession and something being associated with a recession (e.g., Bush is associated with the 2008 recession, but Bush did not cause the 2008 recession). If a recession follows the introduction of Obamacare, regardless of whether or not Obamacare was a cause of the recession it will be politically associated with the recession, which will cost Democrats at the ballot box.
There is a strong possibility we will have another recession before 2016, and it is virtually guaranteed we will have one before 2020 (Why, you ask? The last recession officially ended in 2009, and we have never enjoyed 11 straight years of economic growth). By pushing back Obamacare to the middle of 2015, and assuming the next recession does not start this year or the next, Republicans probably stand a better chance of associating the next recession with Obamacare, regardless of whether the recession starts in 2015, 2016, or 2017. Fair or not, it's part of hardball politics.