It is down to this:  the Supreme Court issue is way more important than any differences of policy, character, or temperament between the candidates in the presidential election.  Nothing else matters, because of this:

• When both the president and a majority of the Court are leftist, the president can act as a dictator, because Congress cannot stop the president and a leftist Court will not stop the president.
• If Ms. Clinton wins the election, the odds are that it will be at least three decades before conservatives regain a majority on the Supreme Court.

Congress cannot stop the president. Until the Obama presidency, American presidents issued federal regulations and executive orders when they wanted to “fill in the blanks” in an Act of Congress, to provide clarification or greater specificity.  But under Mr. Obama, regs and orders are mainly for changing existing laws or creating new ones; they are for doing what Congress had been asked by the president to do but did not.  They are the president’s excuse for ignoring – for exploiting – congressional gridlock, using his pen and his phone.  This is far worse than judicial activism, this is defiance of Congress and the judiciary, this is open disdain for the constitutional model of separation-of-powers.

The judiciary will not stop the president.  A lawsuit can contest the legality of a particular regulation or order, arguing that it was unconstitutional because it was, in effect, a form of legislation, a way of getting around the executive branch.  In the highest-profile recent case involving the constitutionality of an executive order, United States v. Texas, a prominent immigration-case, the lower courts ruled that the president’s executive order was unconstitutional, and, as the Supreme Court was deadlocked at 4 – 4, the lower court ruling remained in place.  However, there was agreement among the commentators that the Supremes were split along ideological lines –  the four lefties voting to reverse, the four conservatives (including Kennedy) voting to uphold. This outcome confirmed the general public impression that a leftist-dominated Court could be counted-on to uphold virtually any executive order issued by a president.

The consequence:  when the judiciary is unwilling to invalidate regulations and orders, it affords the president clear-sailing, freedom to ignore Congress.  We now know what that means when we have a modern Democrat as president: so long as conservatives do not have a majority in the Supreme Court, we live in an autocracy, a de facto dictatorship.

How could this be changed?  With Scalia gone, we have a potentially-deadlocked Court:  4 of the remaining justices are leftist, 3 are conservative, and Kennedy is a swing vote who sometimes give the leftists a majority. But if Clinton were elected and another leftist were appointed as the successor to Scalia, that would give the left a clear majority of at least 5 to 4.  Here is what it would take for conservatives to regain a majority on the Court:

• A Republican president. Let’s call that a 50/50chance, a 50% probability in any election.
• A  Republican majority in the Senate, at the same time as we have a Republican president.  (The Senate must approve all nominations to the Supreme Court.) Recent history:  in the 64 years beginning with the presidency of Dwight Eisenhower, a single party has held both the presidency and a majority in the Senate only 27.5 years – 43%  of those years.  (Nixon never had a Republican Senate in his 6 years, Ford did not have one in his 2, and Bush The Elder was 0-for-4.)   Let’s generously round the 43% up to 50%.  So, the probability of having both a Republican president and a Republican Senate in any year is only 25%, under the basic formula:  when two events are independent, the probability of both occurring is the product of the probabilities of the individual events. 50% of 50% is 25%.
• The departure of a lefty justice at a time when we have both a Republican president and a Republican Senate. The probabilities?  Let’s start with the fact that since 1930 (the nomination of Chief Justice Charles Evans Hughes), there have been only 39 justices appointed to the Supreme Court, of whom 8 still serve, meaning the turnover is only 31 justices in 86 years.  So, we appoint, on average, just one new justice every 2.77 years, meaning the probability of even one court-opening in any year is only 36%.  As there is only a 50/50 chance that the departing justice would be a lefty, the likelihood of an opportunity to replace a lefty with a conservative is a mere 18% (50% of 36%), or once every 5 ½ years.
• Now the punch line: All of that would have to happen at least twice in order to get the conservatives up to a clear majority.  What are the chances of the requisite alignment of the stars and planets occurring not just once, but twice?  The chance of its happening in any year is, 18% times 18%, or just a bit more than 3%.  Three percent per year means once every 33 years! Willing to live under a dictatorship until 2049? Does that work for you?  For your kids?  Your grandchildren?

Temporary relief:  We might not have an autocratic government continuously for the entire 33 years.  Even if Clinton won, we might get temporary relief at a later time if a Republican were elected president.  But that, by itself (absent the other requisite conditions), would not be enough to appoint two conservative nominees to the Supreme Court, it would merely make life a little better for a few years.  Once that president’s term ended, the nation would revert to being at the mercy of a presidential dictatorship.

So, are you anti-Trump conservatives and Republicans  still feeling OK with sitting out this election because of your distaste for Mr. Trump, still dreaming that you could turn this all around with better candidates in 4 or 8 years?  Still confident that a Republican president and Congress in 2020 or later could set things straight again?  Sorry, will not happen.  Even if the Republicans kept control of the Senate this year, despite a Clinton victory, we already know that a Republican-controlled Senate would not have the fortitude to spend 4 whole years continuously refusing to approve any Clinton nominees  to fill the Scalia seat.  So, we would be back to the 33-year scenario.  Are you willing to bet everything on Mitch McConnell overseeing a Republican retention of the Senate and leading a “no” vote on every single Clinton nominee for up to 8 years?