Senator Santorum suspended his campaign today, leaving Governor Romney as the likely Republican Party nominee with Speaker Gingrich and Dr. Ron Paul trailing, but still in the race. This is a fortuitous development for Gov. Romney, as April and May were not likely to be kind. Politics, after all, abhors a vacuum. This situation is likely to result in an exponential growth in Dr. Paul delegates, which has been the focus of the Paul campaign all along. This prediction is based on where the primaries are to be held next, and not accounting for caucus states.

As everyone knows by know, Gov. Romney does not exactly spark a large amount of enthusiasm. For the upcoming primary contests Republican turnout will tank even lower than before. The GOP race next goes to western libertarian-leaning states, the New England region, and the remaining southern and border states which have yet to vote.

April primaries include elections in Connecticut, Delaware, New York, Pennsylvania and Rhode Island. Pitfalls lie for Governor Romney in Connecticut, New York and Rhode Island.

Connecticut sends 25 delegates to the Republican National Convention. Fifteen district delegates are to be allocated to presidential contenders based on the primary results in each of the 5 congressional districts. Each congressional district is assigned 3 National Convention delegates and the presidential contender receiving the greatest number of votes in that district will receive all 3 of said district's National Convention delegates.

10 additional at-large delegates are to be allocated to presidential contenders based on the statewide primary vote. If single candidate receives a majority of the statewide vote (more than 50%), that candidate is allocated all 10 of the at-large delegates.

If no candidate receives a majority of the statewide vote, each presidential candidate receiving 20% or more of the statewide vote shall be allocated delegates accordingly based on their percentage of the vote between those candidates who met the 20% threshold. That means to sweep Connecticut, Gov. Romney has to spend time and money there.

In terms of New York, New York's  92 are awarded as follows: 58 district delegates are bound to presidential contenders based on the primary results in each of the state's 29 congressional districts (using 2010 congressional districts per the 2000 census reapportionment). Each congressional district is assigned 2 National Convention delegates. In addition, 34 At-Large delegates are bound to presidential contenders "winner-take-most" based on the statewide primary results.

If a candidate receives more than 50% of the vote, that candidate receives all 34 delegates.  Otherwise, the delegates are distributed proportionally to those candidates receiving 20% or more of the vote.  Speaker Gingrich has vocal supporters in various upstate congressional districts, and given the eccentricities of New York, Dr. Paul may well get into mid to high 20's with a reduced turnout.  At the very least, Gov. Romney has to spend time and money there as well.

For Rhode Island, the 16 Rhode Island delegates going to the Republican National Convention are proportionally bound to the presidential contenders, 8 each per Congressional district. There is a mandatory 15 percent threshold of the statewide vote to reach in order for a presidential contender to receive delegates. National Convention delegates are distributed equally between the state's 2 congressional districts. Should there be an odd number delegates, the extra delegate is assigned to the congressional district with the largest number of registered voters at the previous general election. Dr. Paul has done disproportionately well in New England States and there is no reason to think Rhode Island is different.

Delaware is a winner take all state so Gov. Romney should receive all of Delaware’s delegates assuming a “normal” turnout.

While it is funny to see Sen. Santorum pull out ahead of losing his home state, Pennsylvania could be a wild card. 59 of the Commonwealth's 72 delegates to the Republican National Convention will be directly elected (their names appear on the ballot) in a loophole-type primary. Delegates are elected separately from a presidential preference "beauty contest". Each of the 18 congressional districts are allocated 3 delegates (54 = 18 districts × 3 delegates/district). One bonus delegate is added to each of the 5 congressional districts that has best supported GOP candidates over the last four years. As a result, Congressional Districts 4, 7, 8, 12 and 18 get an additional delegate. On June 10th, the at-large delegates, chosen by the state's Republican State Committee, will go to the Republican National Convention officially "unpledged". All of Pennsylvania’s delegates are officially uncommitted.

On May 8th, there are primaries in Indiana, North Carolina and West Virginia. None of these states are likely to be romps for Governor Romney, particularly West Virginia, and they are proportional in delegate allocation.

On May 15, Oregon votes. Its own 25 delegates are to be bound to presidential contenders based on the statewide primary vote. A 3.5% threshold is required in order for a presidential contender to be allocated National Convention delegates. This is a vote by mail primary and almost all candidates on the ballot will get delegates.

On May 22nd, Arkansas and Kentucky both hold primaries. It's hard to see Gov. Romney doing well in either state and Dr. Paul may actually have a chance to carry Kentucky, given that his son is a US Senator from that state.

Arkansas' 33 delegates are chosen as follows: 12 district delegates are to be allocated to presidential contenders based on the primary results in each of the 4 congressional districts. Each congressional district is assigned 3 National Convention delegates. If a candidate receives a majority of the vote (more than 50%), that candidate is allocated all 3 of the district's delegates.

If no candidate receives a majority of the vote, the candidate with the plurality (most votes) is allocated 2 delegates and the candidate with the next highest number of votes is allocated 1 delegate.

Twenty-one at-large delegates are to be allocated to the presidential contenders based on the statewide primary results. Each presidential candidate receiving 15% of the statewide vote is allocated 1 delegate. If a presidential candidate receives a majority of the statewide vote, that candidate is allocated the remaining at-large delegates. If no presidential candidate receives a majority of the statewide vote, the remaining at-large delegates are proportionally allocated among the 3 highest vote getters.

Kentucky's 42 delegates are to be proportionally allocated to presidential contenders based on the primary vote statewide. A 15% threshold is required in order for a presidential contender to be allocated National Convention delegates at the statewide level. One can realistically see Gov. Romney running third here.

Then on May 29th, the Texas Primary is held and Dr. Paul is “all in” for his home state. The state has 152 delegates in all. 108 district delegates are elected three from each of the state's 36 congressional districts. Additionally, 44 at-large delegates are elected through a complicated proportionate system.

All of the breakdowns in these remaining races mean that barring some miracle, Gov. Romney has to wait until June 6th to clinch the nomination, when California, New Jersey, New Mexico and South Dakota hold their primaries.

Due to the mathematical complexity, political observers would do well not to count out the Paul or Gingrich campaigns just yet. While their chances of becoming the next Republican nominee for the President of the United States are very slim, they are not without power or influence in the process. In a number of cases in caucus states, it remains to be seen to what extent the Paul campaign will control the delegations heading into a National Convention.