Clean energy is good, but that doesn't mean a national RPS is good.  MoveOn says that:

"taking steps to reduce our dependence on non-renewable fuels like oil makes sense."

Totally agree.  But this isn't what an RPS does.  It cherry picks favorite technologies and then incentivizes those instead of simply defining the goal and then rewarding anyone who takes actions that move us in the right direction.  (For more details, see here.) The reason we haven't gotten a national RPS passed yet in spite of all the effort over the last decade is because of two fundamental truths of the RPS - as they have been framed:

Fewer than 26 states are net exporters of renewable energy, as defined in the RPS (essentially wind, since solar and small hydro are relatively inconsequential on a total % basis).  This means that fewer than 26 senators will find it in their economic interest to sign.

The economic arguments in favor of an RPS are in some cases overstated (for example, the impact that renewables will have on marginal energy costs, while non zero, is probably not sufficient to offset the cash flow out of the non-windy states), and in all cases more readily accomplished by other approaches that are presently included in the RPS' list of preferred winners (e.g., energy efficiency, waste heat recovery, etc.)  

There are alternatives currently being promoted by ACEEE that would include a "Energy Efficiency Resource Standard" that would solve both problems, but making the tent bigger and ensuring greater participation by the states.  Better still would be an RPS that rewarded the goal rather than the path.  Ironically, much of the opposition to those  changes though has come from the environmental community out of concern that a bigger tent would reduce the incentives to deploy favored technologies.  Which - while it may be true - is irrelevant.  The goal, as MoveOn put it ought to be to reduce our dependence on non-renewable fuels, not to deploy technology X.  The consequences of global warming are far too big and far too urgent for us to quibble about the best way to skin the cat - let's just reward people who get it skinned.  

Until we get to that point, an RPS is sound and fury, signifying nothing.  Nice idea, but (almost) politically impossible, and environmentally sloppy.  We can do better.