Getting a few astronauts to Mars and back shouldn't be the goal. That just falls into the same trap that Apollo fell into, the "now what" trap. There is not much to do on mars other than gather rocks, and while that it geologically important, it doesn't exactly capture the imagination. The goal, instead, should be permanent self-sustaining human settlement of space. That will capture imaginations, that will create jobs, and that will turn space exploration from an underfunded fringe to something mainstream and important. A quarter million people living and working offworld by 2020, that should be the goal. It is am ambitious one, to be sure, but it is doable if they just put the effort in.
There are some huge advantages of space colonization that are too often overlooked by more "practical" minds. The most obvious being that it protects the human species from most extinction level events; once we get a sizable population offworld we know that we'll survive even if a giant meteor crashes into the planet.
More practically, as space travel becomes more common, it will also become cheaper and safer. And to get that many people up there in that short time, it'll have to be relatively common. The infrastructure required for such an endeavor will serve the needs of space exploration for a very long time, and make some extremely ambitious manned missions practical. Once there are people living in permenant space stations or on th emoon, lanuching a manned mission to mars will be much easier and much simpler, and that manned mission can not only brinng back rocks and fossils, it can set the stage for permenant settlement of the red planet, further expanding human civilization.
But, if we don't actually try to get a sizable number of people out there, right now, it's just not going to happen. This should have been done decades ago. There were supposed to be cities on the moon and hotels on Mars by now. But we blew it by being lazy and complacent. We can't wait forever, the time is now. Either we get serious about putting people into space or we just give up and wait for the inevitable ELE to claim all of our lives. There is no middle ground.