Actually this should not even be considered a political issue as all people SHOULD be on the same side. Reasonable people should be against police mistreating anyone and anyone attacking police. Unfortunately divisive people make it into a political issues by making it a two sided issue.
There is no question about that, but it has been politicized in the worst way. The DNC missed an enormous opportunity to repair the divide this week, but instead marched out the mothers of those killed in confrontations with the police. Could they have also brought out the mothers of police officers ambushed and murdered? Just like the script they chose in secret emails to discredit Sanders and promote Hillary, the narrative they chose was designed to play to their base. It's sad, and disgusting, actually. The only narratives that belong in politics in this matter is that all violent criminals will be brought to justice, whether it be police abusing the power entrusted to them by using unnecessary deadly force, or those who would attempt to injure or murder police. Crime is crime, period and should be devoid of racial of ethnic bias.