A little over a week ago the Republican Party (again) adopted a series of changes to their rules for the 2016 Presidential Primaries. This represents the third set of changes to the rules that applied in 2012 and should be the final set of changes (the deadline for the Republican National Committee to finalize the rules is September 2014). A more thorough discussion of the changes can be found at Josh Putnam's frontloading website where Josh has done several detailed articles on this issue.
As I see it, there are five major changes from the rules that applied in 2012. First, and most significant, the Republican Party has changed the penalty for those states who try to move into the window (February) reserved for Iowa, New Hampshire, Nevada, and South Carolina or who otherwise violate timing rules (see below on winner-take-all). For large states (those with over twenty-nine delegates), those states will be reduced to nine elected delegates and their three super-delegates (amazing how the RNC members protected themselves from any penalty to their states). For small states (those with fewer than twenty-nine delegates), their delegations will be reduced to six elected delegates and their three super-delegates. Second, winner-take-all primaries may now be scheduled any time after March 15 (in 2012 the date was April 1). Third, the rules now define what qualifies as proportional -- allowing a state to set a 20% requirement to qualify for a delegate and allowing winner-take-all if a candidate gets a majority in a state or district. Fourth, caucus states that conduct a preference vote (e.g. Iowa, Maine, Washington) must award delegates to the national convention based on that preference vote. Previously, the preference vote was not binding and delegates were elected to the next level (and ultimately to the national convention) without regard to the preference vote. States however (e.g. Illinois and Pennsylvania) may still use a loophole primary in which primary voters directly elect delegates separate from the presidential preference vote. Fifth, delegations must be certified 45 days before the national convention (previously it was 35).
While not an express change to the rules, the expectation is that, in light of these changes, the Republicans will probably schedule their convention in late June/early July. (The change from 35 days to 45 days was probably a mistake setting up a conflict with California and New Jersey that could result in a mid-July date being chosen.)
What should these changes mean to the members of the Democratic Rules and By-laws Committee as they draft the Democratic Rules for 2016. My thought is that they should mean very little. The only change that really matters to the Democrats are the changes to the calendar. With the Republicans enacting strong penalties for states that violate the timing rules, the Democrats are free to enact similar strong penalties (maybe a 75% penalty instead of the former 50% penalty). The remainder of the Republican rules changes (i.e. proportional vs. winner-take-all) are making a mountain out of a molehill. If these new rules had been in place in 2012, the primary fight would have been even closer. What ends a primary campaign is not the rules, but cash. When the supporters of the candidate in second place no longer see a path to victory, the money dries up and the race ends.
As far as the scheduling of the convention, the date of the convention only really matters for the purposes of campaign finance laws. Money received before the convention can count toward the "primary election" -- unless the donor is already at the primary limit requiring it to be credited toward the general election. However, any money left over from the "primary" is carried over to the general election. If you are relying mostly on large donors who contribute the maximum, you want to switch over to the general election as soon as possible after you have received the maximum primary donation from your fat cats so that you can tap into the general election funds. If you are relying mostly on small donors who never approach the cap for an election, it really does not matter when you switch from primary funds to general election funds. Under the current system, an earlier convention would not hurt the Democratic candidate, but it is not absolutely necessary. (Under the old-system of public financing later was better to conserve the limited public funds.) If the Republicans go in June or July, my own thought would be that the Democrats should move up one or two weeks -- after the Olympics but before Labor Day.