Think about the gross illogic of that position. If the Senate could nullify the results of elections just because the majority wants to, well there would be very little left to our democracy. This is even more the case when we are talking about unproven and denied allegations from four decades ago. Powell v. McCormack (USSC 1969) establishes that the Senate can NOT refuse to seat Roy Moore if he wins the election. The Senate could vote by 2/3 to expel him but I think it would be extremely unlikely to do so, and doing so would set an insane and anti-democratic precedent that would shatter the GOP (which might not be a bad thing...)
In today's sexually charged political climate, that might be easier than you think...............