CONSERVE MARS WATER!!!
Sadly that's pretty much how liberals are looking at it. Aside from their claims that we'll "destroy the other planets too" they have a song and dance about ending hunger, hatred, poverty etc.
I just tell them that since they're clearly against all forms of progress, we should just start chucking all the worlds nukes and get it done with. Unfortunately they would rather nag and irritate the human race to extinction.