I would argue that hiding the science when politicians don't like it would also impair their ability to continue to support science.

Further, sending a letter threatening to cut funding is much easier than actually cutting the funding. The relevant funding vote isn't until August, and if there is any difficulty (as there almost always is) it could easily become a midterm battle or even go into the next congress. That's not to say the threat is empty, but it's not a done deal either.