When the looting starts.....

 There is currently some discussion of the possibility that Donald Trump will gain support as a response to the protest-related violence in places like Kenosha and Portland.  People who think this will happen point to Richard Nixon's victory in 1968 as a parallel.  However, there's not much evidence that Trump is actually gaining ground.  There are several possible reasons for this, like  the general decline in the number of swing voters and the simple fact that there isn't as much violence today as their was then.  But one additional reason is suggested by answers to a Gallup poll question from May 1968 (the month after widespread riots following the assassination of Martin Luther King):

AS YOU MAY KNOW, A MAYOR OF A LARGE CITY HAS ORDERED THE
POLICE TO SHOOT ON SIGHT ANYONE FOUND LOOTING STORES
DURING RACE RIOTS. HOW DO YOU FEEL ABOUT THIS - DO YOU
THINK THIS IS THE BEST WAY TO DEAL WITH THIS PROBLEM OR DO
YOU THINK THERE IS A BETTER WAY?

Whites thought it was the best way by a 57%-39% margin, with the rest undecided (only 11% of blacks thought it was the best way).  Less educated people were more likely to favor shooting on sight, but even among white college graduates, 45% thought it was the best way.  

No similar question has been asked this year, as far as I know, but that is revealing in itself--"a shoot on sight" policy is no longer a part of serious public discussion.  

The survey also had a number of other questions on race relations.  One was "how well do you think that negroes are being treated in this community":  72% of whites and only 29% of blacks chose "the same as whites are."   Another was "who do you think is more to blame for the present condition in which Negroes find themselves--white people or Negroes themselves.  Among whites, 24% said whites, 57% "Negroes themselves," and 19% are recorded as no opinion; among blacks, it was 45%, 13%, and 42%.  I think that "no opinion" is combining a number of different responses--later surveys that asked the question recorded a substantial number who volunteered "both," and a smaller number who volunteered "neither."  Then there was a question about whether "most businesses in your area discriminate against Negroes in their hiring practices":  among whites, 19% said yes and 67% said no; among blacks it was 64% and 32%.  Then there was a question about whether labor unions in your area discriminated, which showed a similar split.  

[Data from the Roper Center for Public Opinion Research]