Kamala Harris' mom is South Asian, something Donald Trump, Jr. apparently didn't know until a few days ago.  He saw it on a tweet, found that interesting, and retweeted it (which is evidently something Twitter people do). 

That set off a firestorm of protest from the Left, including many other Democratic presidential candidates.  That's because the retweeted tweet also claimed that because Harris' mother is South Asian and her father hails from Jamaica, Harris is not "African-American" or, as she claimed on the podium in the second Democratic debate, the only "black" candidate present.

Now, just to be clear, I have no opinion on whether Harris is black, South Asian–American, Jamaican-American, African-American, or something else, and I could not care less.  None of my business how she defines herself, just as it's none of my business whether Pete Buttigieg is gay — he insists he is, so good for him. 

What's interesting about the Harris tweet and retweet is not the content, but the ferocious reaction it provoked from Democrats.  Part of it is just because someone named Trump was involved, and anything a Trump does is likely to produce outrage on the Left, even things like trying to stave off nuclear war. 

Even that is a bit of a smokescreen, though, for what really bothers Democrats about the incident.  What really concerns Democrats is anything that might affect black voting in 2020. 

If there is one thing that pollsters and political scientists can agree upon, regardless of their own political orientations, it is that African-Americans have to almost unanimously vote Democrat in 2020, and do so in large numbers.  Anything else, and the White House is almost certain to remain in Republican hands.  It is the fundamental bedrock principle of Democratic politics, and Democrats are sensitive to the least bit of vibration suggesting any upset to that vital underpinning.

The Harris tweet (and some subsequent similar ones) did that by questioning the legitimacy of Harris's claim to be black.  Theoretically, if believed by some significant number of African-Americans, and assuming Harris wins the nomination, that might shake the racial solidarity that helped twice elect Barack Obama. 

For this reason, Democratic operatives and journalists immediately attacked the tweeter (along with Trump Jr.) and theorized as well that the whole thing was a false flag operation probably initiated by those pesky Russians intent on keeping their toady Trump in office.  Regardless of whether this conspiratorial idea has any merit, the reaction shows it hit a nerve.  NBC News reported the exact same story twice on Sunday and again Monday, just in case anybody who might be influenced by the claim didn't understand that it was false and nefarious.

Complicating Democratic concern has to be the whole reparations issue.  It's basic Democratic strategy to offer selected groups of voters government goodies taken from non-favored groups.  Reparations seemed like a sure winner for the vital African-American vote.  Unless it's not. 

Maybe this whole tweet storm was a Republican-Russki setup, but if the original tweet at all reflects African-American views, it could be catastrophic for the Democrats, whether Harris is the eventual nominee or not.   

Even the federal government can't give away an infinite amount of money.  Assuming that a Democrat wins, and somehow a reparations regime is established, the payouts become a zero-sum game.  Congress will appropriate some tax dollars, and that money will have to be spread out among the claimants.  At that point, who is really "African-American" and who is not will control how much cash each person gets in his pocket.  If Kamala Harris qualifies, that means some guy in Biloxi who actually is the descendant of slaves is going to get less.

Identity politics is a Democrat invention, and Harris is the Democratic candidate who most relies upon it for traction in the crowded race.  Funny how Republicans, Russians, and Trumps get blamed for its complications and consequences.