Should we care about what a politician thinks about the Age of the Earth? Andrew Sullivan comes up with a far fetched reason - that is, a reason that depends on logical consistency and the laws of physics.
I have another reason. The GQ question for Marco Rubio on the age of the Earth was a gotcha, but it was given to him because he is a "creationist." The fact is that creationism is so contemptuous of modern science that it's impossible for a creationist to back sensible education policies, public health policies, or appropriate legal measures for rape victims.
The modern Republican party is a festival of obsolete superstition and denial of modern science, and that's one good reason never to elect a President who buys into that superstitious nonsense.
And I don't see any relation to any purely hypothetical questions on some other dubious science Nancy Pelosi might or might not be asked about someday. Politicians should be graded in the actual universe, not a hypothetical one. If some Democrat says that we ought to include pyramid power in our national health insurance he will make an immediate entry on to my eighty-six list - but not until he does say it or write it, whatever you might guess he would say about it.