Under current Republican rules, March 15 is the first day that a state or territory (other than the first four) can hold a winner-take-all or winner-take-most primary.   Four of the five primaries scheduled for this week have some kind of winner-take component (at least for the state-wide delegates).  This week also features the home states (and perhaps the last stand) of Senator Marco Rubio of Florida and Governor John Kasich of Ohio.

As discussed Friday night, Illinois is an unusual state — especially on the Republican side.  In all likelihood, the results will resemble a winner-take-most primary with three delegates going to the candidate who finishes first in each of the eighteen congressional districts and fifteen delegates going to the candidate who finishes first state-wide.    However, because in the congressional districts delegates are on the ballot and are directly elected, there is a chance that some delegates might be elected even if their presidential candidate loses the district.  Such an “upset” is most likely to happen in close districts.

Missouri is a pure winner-take-most state.  However, unlike most states, the winner of the congressional districts will get five delegates from each district (rather than the normal three) and the state-wide winner will only get twelve delegates.

As noted above, Ohio and Florida are winner-take-all states (ninety-nine delegates in Florida and sixty-six in Florida).  It is hard to see how any candidate wins enough delegates the rest of the way to get the nomination if they are shut out in Ohio and Florida.  Of course, some of the candidates are probably hoping for a deadlocked convention.  For both states, the reality is that Trump will end up between 35-40%.  If the supporters of the other candidates engage in tactical voting, they can beat Trump. That is probably easiest to do in Ohio where it is clearly a two-candidate race.  In Florida, the difficulty is who becomes the consensus anti-Trump candidate.  Cruz and Rubio are neck-and-neck for second in the polls, and there are a large number of early votes already banked.  For Senator Cruz, there is the additional problem that he is not a likely consensus candidate at a deadlocked convention; so he has last incentive to team up to assure that nobody has more than 1,000 delegates heading into the convention.

North Carolina is the only one of the five states that will proportionately allocate delegates on the Republican side.  All seventy-two delegates will be allocated based on the state-wide results with no threshold and no winner-take-all trigger.  Thus, all four candidates will probably win some delegates out of North Carolina.

One key thing to note on the Republican side as we start winner-take-all and winner-take-most states.  For a candidate’s name to be formally placed in nomination (assuming that the convention does not change the rules), he needs a majority (not a plurality) of the delegates in eight separate delegations.  So far, the count is:  Trump — 8 (South Carolina, Alabama, Georgia, Massachusetts, Tennessee, Maine, Hawaii, Mississippi); Cruz — 3 (Texas, Kansas, Idaho); Rubio — 1 (Puerto Rico); and Kasich — 0.  Whomever wins Florida and Ohio will add those states to their categories, and it is more likely than not that the same will be true in Illinois and Missouri.

On the Democratic side, as always, delegate allocation is proportional.  Florida has twenty-seven congressional districts ranging from three delegates to eight delegates each (140 district delegates total) with twenty-eight party leader delegates and forty-six at-large delegates (214 delegates total).  Illinois has eighteen congressional districts ranging from four delegates to nine delegates each (102 district delegates total) with twenty party leader delegates and thirty-four at-large delegates (156 delegates total).  Missouri has eight congressional districts ranging from four delegates to ten delegates each (47 district delegates total) with nine party leader delegates and fifteen at-large delegates (71 delegates total).  North Carolina has thirteen congressional districts ranging from four delegates to eight delegates each (70 district delegates total) with fourteen party leader delegates and twenty-three at-large delegates (121 delegates total).  Finally, Ohio has sixteen congressional districts.  If you don’t think that Ohio was ruthlessly gerrymandered in 2011, twelve of the sixteen districts have four delegates each (compared to the national average of six delegates representing a swing district).  Of the remaining four districts, two have eight delegates each, one has twelve delegates, and the last district (Ohio 11th) has SEVENTEEN delegates.   In total, Ohio has ninety-three district delegates, nineteen party leader delegates, and thirty-one at-large delegates (143 delegates total).

As discussed in the previous weeks, it is hard to gain delegates in the congressional districts.  In districts with an odd number of delegates, the winner will have a one-delegate edge. but — with rare exceptions (e.g. Ohio 3rd and Ohio 11th) — it takes a double-digit margin (or more) to pick up extra delegates in the congressional districts.   It is a little bit easier to pick up extra state-wide delegates, particularly from the at-large delegates (outside of Missouri, it only takes a 4% or less margin to pick up extra at-large delegates this week).   This math can make a big win in a medium-sized state (like Missouri) matter more than a narrow win in a big state (like Florida).

In both parties, this week is one of the bigger weeks in terms of total delegates available (second largest on the Republican side and third largest on the Democratic side).  It is also the mid-way point for both parties.  More delegates will have been allocated (or at least theoretically allocated in the case of some caucus states) as of Tuesday than will remain to be allocated.  As such, delegate counts will become more and more important as each week progresses.  The time is starting to run out for candidates to make dramatic changes to the delegate picture.  On the Republican side, that is a problem for all four candidates (as all are beneath 50% of the delegates allocated to date).  On the Democratic side, time is the friend of Secretary Clinton as it was for President Obama eight years ago.