Why it matters that Rubio thinks it matters that he's not a scientist

Krugman tells us why we should care that Marco Rubio thinks it doesn't matter how old he thinks the earth is:

But here’s what you should realize: when Rubio says that the question of the Earth’s age “has zero to do with how our economy is going to grow”, he’s dead wrong. For one thing, science and technology education has a lot to do with our future productivity — and how are you going to have effective science education if schools have to give equal time to the views of fundamentalist Christians?

More broadly, the attitude that discounts any amount of evidence — and boy, do we have lots of evidence on the age of the planet! — if it conflicts with prejudices is not an attitude consistent with effective policy. If you’re going to ignore what geologists say if you don’t like its implications, what are the chances that you’ll take sensible advice on monetary and fiscal policy? After all, we’ve just seen how Republicans deal with research reports that undermine their faith in the magic of tax cuts: they try to suppress the reports.