There is something very strange about the national political reaction to the protests in Ferguson, Mo., (and nationally) over Michael Brown’s shooting. The protesters are angry, and they’re not aimlessly angry. They have a specific set of policy grievances about policing and criminal justice that are shared by a large slice of the electorate, particularly the Democratic primary electorate.

Yet no national Democratic politician, nobody of the sort who is likely to mount a presidential run anytime soon, has risen to give voice to the anger we’re seeing in Ferguson. Nobody seems eager to make police abuses or racial injustice a key issue in a national campaign, even though an awful lot of Democratic voters could be activated on those issues.

Why not? African-Americans are a hugely important Democratic Party constituency. Gallup data suggests 22 percent of self-identified Democrats are black. Exit polls showed black voters made up one-third of North Carolina primary voters in 2008 and a majority in South Carolina. If there were an incident of similar salience to a group that made up such a large share of the Republican base, you can bet a number of Republican politicians would be lining up to associate themselves with the protesters.

There are answers to the “why not?” question, but I don’t think they make the quiet on this issue sustainable.