Daas Torah is clearly not okay with it. All Gedolim who have addressed the issue of whether we may vote for a candidate that supports, on a policy level, immorality — have unequivocally said NO in big capital letters.
(The fact some rabbi may have supported a specific candidate that supported immorality, says nothing to the fact whether said rabbi was aware of all such candidate’s policy positions in question.)
And don’t kid yourself that toeiva marriage “will not effect the spiritual atmosphere that much if at all.”