It is highly odd that Oliver Willis would attribute murdering cops to those who hold Republican views.

ARREST RATES. In the debates over whether felons can vote, both Republicans and Democrats seem to agree implicitly that felons will tend to favor Democrats. I have never heard anyone even hint the opposite.

That is consistent with General Social Survey data showing that the odds of a Democrat or Independent reporting having been arrested or charged with a crime are 122% higher than the odds of a Republican reporting being arrested or charged with a crime. Among those who report having been arrested or charged, only 12% are Republicans. The others are 9% Independent, leaning Republican; 18% Independent (no leans); 18% Independent, leaning Democratic; 40% Democrats. (Of course, arrest is not the same as offending or conviction, but the political makeup is likely to be in the same general direction.)

I am aware of no data on the party identification of murderers in general or of cop-killers in particular, but there is no reason to suppose that the political orientation of cop-killers is any more Republican than the general criminal population, which everyone assumes (and GSS data indirectly suggests) is disproportionately Democratic.

ANGER AND HAPPINESS. As to anger and happiness, in the GSS Republicans report being much happier, being less likely to be angry at someone, and less likely to be mad at someone or something. When angry, their anger lasts less time, and they are less likely to plot revenge.

Compared to non-Democrats, on the other hand, Democrats report being somewhat less happy and when angry, their anger tends to last longer. On being angry at someone, being mad at someone or something, and plotting revenge, the results are not significant because Independents are (usually insignificantly) more extreme than Democrats on these issues).

I don't know whether Democratic views cause criminality or anger -- frankly, I doubt it. The likelier causal direction is that unhappiness with one's lot in business and in life tends to make someone Democratic, a probable example of what social psychologists call motivated social cognition.