So I've now read a couple of opinion pieces about how Gingrich remaining in the contest could actually help Santorum. Jonathan Karl provides passes on (without necessarily endorsing) the concise argument Gingrich is making for this counterintuitive assertion as follows:
If Gingrich drops out, he argues, two things will happen:As I'll explain below, however, the first argument shows a total lack of understanding of how the delegate selection process works, and the second argument is moot. In short, Gingrich remaining in does not help Santorum in the least.
1) His vote gets divided between Santorum and Romney. A larger percentage would go to Santorum, but at least sotme goes to Romney, allowing him to accumulate more delegates; and,
2) Romney is then able to aim all of his considerable firepower at Santorum, destroying him with negative ads the way he twice destroyed Gingrich (in Iowa and Florida).
So, Gingrich argues, if he drops out some of the voters that would have voted for him will go to Romney, thus giving Romney more votes, thus giving Romney more delegates. Furthermore the key to anybody (including Santorum) defeating Romney is to stop him from accumulating enough delegates to win on the first ballot. Scott Conroy buys this argument without question. As he writes:
If Gingrich were to drop out, various polls show that Santorum would garner the majority of the former speaker’s support. Nonetheless, in a two-man race with Romney, the math is more difficult for Santorum, not less. Romney figures to win enough of the delegates Gingrich otherwise would have taken to prevent Santorum from overtaking him.While Conroy and Gingrich are correct that it is more important for Santorum to deny Romney delegates than to gain delegates himself, and a Gingrich exit will likely lead to more votes for Romney, they both just assume that more votes means more delegates and in many situations that would just not be the case.
First of all, some states' at-large delegates and many states' district-level delegates (which is where most of the delegates are selected) are selected on a winner-take-all basis. Under these rules it doesn't matter whether Romney wins 40% or 43% of the vote, as long as he finishes with more votes he wins all the delegates at stake. The increase in votes doesn't net Romney a single new delegate. Yet, if in the same state or district Santorum's vote were to go up from 38% to 45% because of Gingrich exiting Santorum will have succeeded in denying Romney all of the delegates at stake for that district or state. In this scenario a greater number of votes cannot lead to more delegates for Romney and may lead to fewer.
Even when delegates are allocated proportionally there is often thresholds that candidates must meet. It is often the case that votes for candidates that do not meet the threshold are essentially thrown out when it comes to allocating the delegates. Thus if Gingrich fails to meet the threshold (often 15% or 20%) and votes for Gingrich are wasted. If the votes had gone to Romney and Santorum instead, as long as Santorum would end up with more of those votes than Romney, Romney would end up with fewer delegates (despite receiving more votes than before). Consider the following example. Suppose there are 30 delegates to be allocated proportionally with a 20% threshold. Suppose further that with Gingrich in the race the results would be Romney with 40%, Santorum 40%, Gingrich 15% and Paul 5%. In this case Romney and Santorum would each receive 15 delegates. If when Gingrich exits, Romney ends up with 42%, Santorum get 48%, Gingrich ends up with 4% (he's still on the ballot) and Paul gets 6%, then Santorum will win 8/15 of the viable vote compared to 7/15 for Romney and hence Romney will get only 14 delegates. Again despite getting more votes, he ends up with fewer delegates. In any of these situations where Gingrich would not be viable anyway, the extra votes that go to Romney cannot help him (unless Romney was himself in danger of not being viable). Proportional allocation also requires rules as to how round fractional delegates. There are many ways to do this, but most states in this process adopt rules which in some way favor the lead vote getter. So if Gingrich's exit from the process leads to Romney coming in second instead of first in a district or state that would also result in fewer delegates for Romney despite more votes.
A final factor to consider is that in some states and districts, if a candidate receives over 50% of the vote he wins all of the delegates (essentially the contest becomes winner take all). If Gingrich's exit would lead to Santorum winning more than 50% of the vote (as would likely have been the case in many parts of Alabama and Mississippi last Tuesday), then Romney would up with 0 delegates (despite having more votes than he otherwise would have had). Admittedly this could work in the other direction. If Gingrich's exit would lead to Romney breaking the 50% barrier, a small increase in votes could lead to a great increase in delegates. Overall, though, since more of Gingrich's votes would go to Santorum there is a greater chance that a Gingrich exit could lead Santorum over the 50% mark than that it could lead Romney over that mark. When combined with the other situations above, it seems to me that despite leading to more votes for Romney, a Gingrich exit would in all likelihood lead to fewer delegates for him.
As for the second Gingrich argument that his exit would allow Romney to concentrate all of his attacks on Santorum, I laughed. Since Florida that's what Romney has been doing anyway. If Gingrich remains in the race, it won't distract Romney from attacking Santorum for a second.