with respect to your request for alternatives, in this case, i'd simply eliminate the line.

I think that getting 20% of our energy from renewables covers the policy changes that would get us towards a reduction in demand for foreign oil.

In reality, if we were gettting the SAME absolute level of oil imports in 2020 as today, it would be a big, big change -- it would mean that we were obtaining our growth from non-foreign sources (most likely renewable, with some nukes) -- and that would be huge!

Now, if you need a third bullet, I would suggest making it a relative goal, not an absolute goal:

"Reduce the proportion of our energy derived from foreign oil by 20%"

Maybe this is more achievable?

If you have the stomach for it.

Bring back the 55MPH speed limit
That would be an immediate 10-15% savings.

Require that all companies with more than 100 employees have at least 15% telecommuters
There's another 10%.

You could do other things: high tarrif on truck shipments, subsidize E85 fuel, etc.

Of course, I think what Jerome is calling for (and what I would want as well) is something a little less drastic: gradual improvements in fuel efficiency, public transportation, and conservation all adding up to a 20% drop over the next 15 years.

Nearly 70% of petroleum is consumed by the transportation sector in the US.  With technology that exists right now, the average fuel efficiency could be increased by something approaching 100% by switching to lighter vehicle construction, smaller cars, much more emphasis on diesel and widespread use of hybrid technology.  If plug-in hybrids were to be widely adopted, the potential for a several-fold improvement exists.  However, a big shift to higher efficiencies would likely be offset by more driving unless fuel prices were kept high.  

Re "The goal of a 20% reduction in imported oil strikes me as both impractical and politically un-smart", it is likely that the decline in production on the backside of Peak Oil will equal or exceed 20% by 2020 (15 years from now), whether or not this policy is implemented. So the Democratic Party can adopt this policy for free.

I advocate using all available incentives and regulatory changes to boost and facilitate increased biodiesel and ethanol production ASAP. (And don't tell us about Pimentel -- he has been thoroughly discredited by multiple studies; biodiesel and ethanol, especially cellulosic ethanol, do pass the energy ratio test.)

I think people who make comments like this do not understand 1) just how much oil the US uses compared to the rest of the world and 2) how much greenhouse gas emissions need to be reduced in order to avoid catastrophic global warming.

The United States produces almost double the greenhouse gas emissions of Western Europe, which has roughly 400 million people.  Granted, we are significantly less geographically compact, but it still seems more than reasonable to reduce our oil consumption by 20%, leaving us using only maybe 50% more per capita than our European friends.  Since 2/3 of the oil we use goes to cars, all we would have to do is increase the mileage of the average freeway vehicle by 50% (which can easily be done with existing technology) and we would fly past the 20% goal, without even reducing driving (which we should also do).

In order to stabilize atmospheric CO2 at about 20% more than current levels by 2100, we will need to reduce global greenhouse gas emissions by 80% by 2050.  With other extremely populous countries like China and India experiencing strong economic growth, it is reasonable to assume that the United States will need to reduce its GHG emissions my more than 80% over the next half-century in order for the world to achieve the overall 80% reduction.

Check this out.  It's a java applet that allows you to see interactively, based on the Intergovernmental Panel on Climate Change models, what reductions in GHG emissions are necessary to achieve various stable atmospheric levels and temperature combinations.