This question is similar but different to https://politics.stackexchange.com/questions/10978/can-the-senate-postpone-confirming-a-new-supreme-court-judge-virtually-indefinit.
The Republican-led Senate has refused to confirm the appointment of Merrick Garland to the vacant seat on the US Supreme Court.
If Clinton wins the presidential election, but the Democrats fail to take control of the Senate, the Senate could indefinitely block Garland's appointment, essentially reducing the Supreme Court to an 8-justice court.
Now, what if another SCOTUS justice were to pass away, resulting in two vacancies? And then a third justice passed, away, leaving only six justices? Or, to take an unlikely example, if a tragedy occurred that resulted in the deaths of all remaining SCOTUS justices?
Is there a point at which the Senate Republicans would be forced to confirm a Democratic president's nominee in order to maintain a minimum number of justices on the US Supreme Court? Or could the number of SCOTUS justices theoretically dwindle to zero if all of them passed away during Clinton's time in office? What would happen then?