Critiquing Democrats is not an endorsement of Republicans
OK.
Just be aware that doing so publicly, especially around election time, increases the probability of Republicans getting elected. So ask yourself if its the right time and place - regardless of what your intentions are, what sort of effects will your actions actually cause in the world?
IMO, the best time and place to make your opinion on Democratic policy known is the Democratic primary election and who you choose to help campaign for the primaries.