Hillary Clinton should be able to appoint all nine justices without a shred of danger to out rights. That this is not so is (not necessarily) an argument for voting for the Republican candidate - it's an argument for action to reduce the powers exercised by that court, peacefully if possible.
The exercise of such power that the fate of the nation hangs on a single justice means that the coup has already taken place, and that it may be necessary someday to take action to restore what has been lost.
Brutus, Anti-Federalist XI, 31 January 1788 http://www.constitution.org/afp/brutus11.htm
Hopefully there can be a Constitution convention and fix the problem, so it doesn’t matter who wins.