The reason that analysts like myself caution people that we can't really know who the new mainstream frontrunner will be until the SC primary (or even for sure that will be a new one, although this is all but certain at this point) is bc black voters are immensely influential in
in the southern states, this you know. But what you may not know is why they are so powerful. Sure, you probably know that that states like SC are racially diverse, so of course, voters of color are going to be important in the Dem primary. Other than party ID, the most reliable
predictor of vote choice for an individual comes from whether a voter is black. Due to civil rights issues, black voters break for Dems at rates similar to the rates that partisans break for their parties: in general, 90% of black voters will break for the D candidate in an
election, which is why the Trump campaigns fake efforts to win over black voters amounts to little more than a public relations effort. Until this past decade or so, Latino & Asian voters have been more split, indeed, George W Bush actually won the majority of Latinos in his race
in 2004. However, by 2008, the base of the Republican Party- & the media environment that drives it- had moved so sharply to the right on immigration that it forced the party's prez nominee to abandon his own comprehensive immigration bill & Romney in '12 was forced into his
infamous "self-deportation" plan, along w AZ's harsh immigration law that provoked national backlash. This hard shift to the extremes made the base happy, but pushed Latinos away from the GOP. Right now, only mildly, the real pain will come as Millennial & Gen Z Latino voters
become a larger portion of that voter pool. Asian voters have also noticeably shifted to the left over this time period, responding to rising nativism in the GOP's platform & rhetoric. Last year, political scientist @AshleyJardina published 1 of 4 works I consider to combine w my
own research to build a body of literature that sheds light into the profound changes we are seeing in American political behavior right now. Her contribution was to assert that whiteness had become a racial identity & that identity politics, long constrained to the left, now
permeated the right-primarily via white identity politics. This is bc whites are now feeling threatened, their dominance is ending & they are pushing back. This is, of course, not constrained to low education whites, but certainly more conducive within non-college edu whites, bc
edu tends to offset threat as well as expose people to diversity & humanize "the other." But back to SC. The reason black voters are so powerful there is that in the South, the Dem Party is now majority black. In GA, in 2008, black voters cast the majority of Democratic ballots.
That is bc whites in the South are voting via their racial identities, as you can see in this graph. Fully 75% of southern whites didn't vote for the D senate candidate in 2018- these are remarkable numbers!!! What it should look like is the northeast & west regions, about 50/50. 
Now, if you are sharp eyed you probably noticed there is a 2nd region in which white identity politics is prolific- the Midwest. Like their southern counterparts, there is something unique, something different happening to whites in the Midwest that is not happening to whites in
NE & the West. Obviously, there is variation by region on ideology/party. There are more Ds/liberals in the West & the NE than their are in the South & Midwest. But the differences do not explain why only a quarter of whites in 2018 cast ballots for Dem Senate candidates in 2018
