Hypocritical statements by opponents aside, there are problems with Perry's proposal and supporting arguments.

Fuel diversity, grid reliability and security arguments are weak.  Opponents are right that a mostly gas grid with some (up to 30%?) renewables would provide sufficient reliability.  Also, this proposal would allow all qualifying coal and nuclear facilities to have all their costs covered (plus a specified profit) no matter how high their costs are.  To the extent that the grid reliability benefits of these baseload plants are of any tangible value, a finite subsidy should be awarded.

The real reasons to support existing nuclear are environmental.  For that reason, It deserves support similar to renewables'.  Reasons to subsidize coal are essentially non-existent.  The tragedy is that they feel they have to come up with non-environmental reasons to support nuclear, and that they also have to support coal, just because Trump and the GOP are in charge.