I favor:
NASA Exploration of the Moon to determine if there is minable water.
If there is minable water, this leads to various paths and details which for brevity I will skip.
If there is not minable water, then I see the Moon as a destination in the short term as being less attractive. Without minable water, the first thing I would do is put doing a Manned Mars further into the future- maybe within the time frame as that outlined in President's plan or further out. Next, would have NASA look for other space resources which could possibly be commerically mined- maybe water in NEOs, or other types of mining of NEOs like oxygen and metal ore processing. Or maybe if NASA/govt were to put a nuclear reactor on the Moon, then perhaps some commerical venture could work, if their electrical power was subsidized by govt- govt could provide electrical power at say $1 per kwh or something. For instance maybe oxygen extraction on the Moon would be possible- and with the oxygen part of rocket fuel requirement provided at fairly reasonable cost this could lead to lunar tourism or sample type return operations. Another leg, would be for NASA to "build up" Earth/moon L-1 and/or L-2. Also part of this may be the idea of Mars cycler. Maybe start with Lunar cycler. These cyclers are fairly massive giving lots of living space and radiation sheilding- crew transfer to them, live in them during voyage to Mars (or the Moon), then leave them, staying on Mars until the cycler returns, then getting back on it again.
Generally, what I'm looking at is avoiding what happenned with Apollo, so what is needed is for there to be more space infrastructure- and this infrastructure isn't govt owned and maintained. This is done so, when we send crew to Mars, there will be follow through. It won't be a few crew landing on Mars, then the govt looking to reduce costs by canceling the program [once all the "fun" is gone]. Following this logic, it doesn't make sense for govt building some lunar base for crew play around on- that just one more item that needs govt money in order to maintain. If NASA really wants a lunar base, it should rent one for a couple years, but I don't think NASA actually should need a lunar base in the short term- whether there is commerically minable lunar water or not.