It's because health care is part and parcel of the economy, that's why.
Not only that, but American voters are already all too painfully aware of how the GOP desires to focus on a single issue just so nobody will notice when they slip another dictatorship under the door.
There's also the matter of the demographics of voter polls--the female demographic plus the latino demographic against Romney are adding up.
No problem. In the same poll healthcare comes in at only 8%. So the premise stands.
It's still part and parcel of the economy, which is why cons keep bringing it up--Ryan in particular.