He already has - in his tv speech last week.

You mean the speech to the Joint session?

If so, IMHO it's still too intellectual for TV attention spans. He needs a soundbite. Something like "I don't want people being bankrupted by medical bills." That forces his opponents to insist that neither do they, in which case they need to explain how their policies will reverse the trend. So they're on the back foot and Obama is setting the agenda. Then he could hit the grandma button: "every year there are hundreds of thousands of new grandmas on Medicare. That's why Medicare costs are going to keep growing. Our options are to pay the bills, or to abandon grandma to fend for herself. I believe that most Americans revere and respect our elders and as much as we hate taxes, we want to see grandma's bills paid." That gives him lots of "Grandma deserves Healthcare" opportunity to set the agenda again. Sheesh, he could have a field day. ;-)