The contests this Saturday have the potential to end one or more Republican candidacies, while Hillary Clinton is faced with a stronger than expected challenge from Bernie Sanders, who proudly describes himself as a “Democratic socialist.”

However, Saturday’s contests are unique in that Democrats and Republicans are not competing in the same states on the same days. Republicans go to South Carolina this Saturday, while Democrats are three time zones away in Nevada. After South Carolina, Republicans go to Nevada next Tuesday, while Democrats have their South Carolina primary next Saturday.

The nature of each contest is also different: South Carolina does not have party registration, which means that independents can influence the outcome – especially since the Democrats don’t vote for another week. And while Nevada has party registration, same day registration is permitted for the Democratic caucus, meaning that a new voter or Republican/Independent could be a “Democrat for a day” and vote in their caucus. Republicans do NOT have same day registration, and their rules require that the voter be registered as a Republican by February 13.

South Carolina Republicans (2/18 RealClearPolitics poll average): Trump 35, Cruz 17, Rubio 17, Bush 10, Kasich 10, Carson 6)

The context for South Carolina is different in several ways from the run up to New Hampshire in the aftermath of the Iowa caucus: (1) the Republican field has now winnowed down to six serious candidates, (2) Donald Trump is entering South Carolina with the aura of a winner, and it doesn’t hurt that he has a substantial lead in South Carolina, and (3) the “moderate track” (originally explained here) has not securely established itself – Rubio, Kasich, and Bush are still fighting for this prize.

Donald Trump has the easiest task of all six contenders: he only needs to win by a decent margin to be perceived as the “top dog.” Given that exit polling shows he has a broad base of support, that puts him in good shape in South Carolina. Because while the South Carolina primary is considered an early indicator of the “Southern vote”, its electorate have been somewhat shaped by northern migration into its coastal counties and suburbanization from Charlotte, North Carolina. This dynamic (as well as a split “Deep South vote”) was how a moderate John McCain carried South Carolina in 2008.

Ted Cruz’s challenge is different: while he is adequately funded, has a good ground game, and a victory (Iowa) under his belt, he has to be able to defeat Trump – especially in the South. If a Trump win in South Carolina creates the climate for a Southern sweep on “Super Tuesday” on March 1, that puts more pressure on Cruz to win upcoming primaries in the bigger states, although the more moderate primary electorates of those states (as Rick Santorum found out in 2012) makes this task more difficult.

Rubio has a similar challenge as Cruz, although in his case, he needs to establish his legitimacy in the short term by placing better than third in a primary/caucus contest. Additionally, he needs Bush and Kasich to exit the race so he can consolidate the more moderate/establishment vote and be a credible threat to Trump in the larger, more moderate states which will be weighing in soon on their candidate preferences.

Bush and Kasich (Ben Carson as well) have a more basic challenge: survival. Jeb is essentially “going for broke” in South Carolina by bringing in George W. Bush to campaign for him. However, it’s worth noting that “43” was last on the general election ballot in South Carolina in 2004, and he last fought a primary contest there in 2000. Kasich’s challenge is to parlay his second place finish in New Hampshire into eventual victories in less conservative primary states like Massachusetts, Vermont (both vote on March 1), and Michigan (which votes on March 8). However, without much in the way of current conservative support, he risks (with his more limited campaign infrastructure) “dying on the vine” before then, because voters in those states are not likely to appreciate the fact that Kasich must in the short term face a gauntlet of more conservative states in the 20 days between New Hampshire and “Super Tuesday” – this belief in future victories (while writing off the present) similarly doomed the Giuliani campaign in 2008.

Nevada Democrats (2/18 RealClearPolitics poll average: Clinton 47, Sanders 46)

New Hampshire established Bernie Sanders as a credible contender. Now he has to broaden his appeal to minorities and union members. Nevada has surprisingly (given its Hispanic/union population) been friendly to the Sanders campaign, and if he wins (or even comes close to knocking Hillary off), he would be in good shape for the plethora of primaries/caucuses on March 1 (also known as “Super Tuesday), although he may get an unfriendly spate of interim publicity from the South Carolina caucuses – South Carolina’s Democratic electorate is majority black, and Hillary Clinton has a big lead there.

Looking down the road

Once both South Carolina and Nevada have voted, Super Tuesday is on Tuesday, March 1, and it is the busiest day of the 2016 primary season. 14 states vote, and all 14 states have Republican primaries/caucuses, while Democrats have 11 contests (Louisiana votes on March 5, and early voting begins on February 20). While there will be some determinations of winners/losers before then, after March 1, media attention will be focused on 2-3 candidates  from each party. What’ll be interesting on the Republican side is when/if they can have one “moderate candidate” in the race capable of competing with Trump and Cruz.