I'm aware of this...I've literally been arguing that the median voter is center-left/left on economics and center/center-right culturally for years. Look through my post history.
Congress, however isn't actually a representation of what the populace supports. If you vote on it now, it will go down in flames. And Congress will see it as a liability for years to come. Step one is changing Congress. Step two is pass agenda.
We're still on step one.