The biggest barrier to mounting a credible election campaign is getting funding. Scientists are good at getting funding when it comes to writing grant applications, but raising real money in most elections means spending a couple hours every night of the campaign calling people and begging for money.

They don't talk about this and you don't see it on TV, but that's actually the biggest challenge most new candidates face. Policy statements, talking to voters, and giving speeches is a pretty minor part of it.

Most scientists just aren't going to be successful in that environment.