I'm not the only one who has noticed that Democratic caucus and primary turnout so far has been down as compared to 2008 and that Republican caucus and primary turnout has been up as compared to either 2012 or 2008.

Anna Greenberg, the Democratic pollster, made the same observation on a joint American Enterprise Institute/Brookings Institution/Center for American Progress panel last Thursday. The results of the South Carolina Democratic primary Saturday confirm the trend. Total turnout was 370,000, down from 30 percent from 2008's 532,000 (I'm rounding off figures to the nearest thousand, and the 2016 numbers may be off a little from the final returns and exit poll numbers).

Many commentators have noticed that blacks constituted a higher percentage of South Carolina Democratic voters this year, 65 percent according to the exit poll, than they did in 2008, 55 percent. But this represents not a surge of blacks into the electorate, but rather the fact that black turnout declined by only 18 percent, whereas white turnout fell nearly in half, by 44 percent.

Below I've given the totals, extrapolated from exit polls and current returns, for all voters, black voters and white voters, by candidate preference in 2016 and 2008. Edwards, as some may have forgotten, is John Edwards, the one-term senator from North Carolina who was born in South Carolina (the only county he carried is the one where he was born) and 2004 Democratic vice-presidential nominee.

All voters Black voters White voters Total votes 2016 370,000 240,000 129,000 Clinton votes 2016 272,000 208,000 68,000 Sanders votes 2016 96,000 31,000 61,000 Total votes 2008 532,000 293,000 229,000 Obama votes 2008 295,000 228,000 55,000 Clinton votes 2008 141,000 56,000 82,000 Edwards votes 2008 94,000 6,000 92,000

Observations:

1. Clinton got many more votes from blacks this year than she did in 2008, but fewer blacks voted for her this year than voted for Obama in 2008. This is evidence that can be cited by those who have predicted that Democrats will have a hard time inspiring as many black voters to the polls in November than they did when the first black president was on the ballot.

2. Sanders did miserably among black voters. Historically, black Americans have tended to vote near-unanimously, in primaries and in general elections, for candidates they feel have the deepest commitment to civil rights issues. This is a rational response for people who feel themselves to be members of a minority that has been the object of discrimination and bad treatment.

Those feelings seem to be operative today. Incidentally, the place where Sanders ran closest to 50 percent was Pickens County, the home of Clemson University.

3. Clinton and Sanders both got significantly fewer white votes than Clinton or Edwards got in 2008. It is as if many South Carolina whites, with an ancestral attachment to the Democratic party, have decided to secede from it. White turnout in South Carolina's Republican primary was 707,000, compared to 129,000 in the Democratic primary.

4. One countervailing factor should be kept in mind. There was considerable suspense in the runup to the South Carolina primary, if not about whether Donald Trump would win, at least as to who would finish in second, third and fourth place. Trump, Marco Rubio, Ted Cruz and Jeb Bush stumped through the state repeatedly.

There was little suspense, however, about who would win the Democratic primary. Anyone paying much attention knew that most primary voters would be black and a large percentage of blacks would vote for Clinton. She campaigned a little in the state, Sanders hardly at all. So the weak Democratic turnout can be ascribed, in part, to the lower suspense level, something that will probably be true of Southern primaries (except maybe in states with low black percentages, like Oklahoma and Kentucky) on Super Tuesday and later, and may be true of most contests outside the South as well.

That said, the shrinking Democratic primary numbers are not a sign of strength for the Democratic party or Clinton.