When the results from Tuesday's Super Tuesday primaries, billed as a de facto national primary, are finally in, the odds are high that the two major parties' nomination paths will diverge significantly.
Sen. , R-Ariz., is likely to emerge as the prohibitive favorite for the GOP nomination, while a close delegate fight between Sens. , D-N.Y., and , D-Ill., continues.
National polling was of limited value prior to the early single-state contests. But with 22 states holding Democratic primaries and caucuses and 21 states holding Republican contests, national polls are now more useful as rough gauges of the candidates' standings.
These polls, corroborated by state-level polling, show McCain pulling away from former Massachusetts Gov. and former Arkansas Gov. , while Obama appears to have erased Clinton's lead and has possibly even moved ahead.
A Cook Political Report/RT Strategies poll [PDF], conducted Thursday through Saturday afternoon with 855 registered voters nationally, shows a tight Democratic race and McCain pulling ahead among Republicans surveyed. The poll has an overall 3-point error margin.
Among the 376 Democrats and Democratic-leaning independent voters, Obama had 43 percent to Clinton's 37 percent, with 20 percent not sure or volunteering someone else. That Democratic sampling has a 5-point error margin.
Among the 308 Republican and GOP-leaning independents, McCain leads Romney 39 percent to 24 percent, with Huckabee at 18 percent, Texas Rep. Ron Paul at 6 percent and 14 percent unsure or for someone else. The GOP sample has a 6-point error margin.
Other national polls released Monday or over the weekend also showed the Democratic contest extremely close. Surveys by CNN/Opinion Research Corporation, USA Today/Gallup and Pew Research Center all showed Clinton and Obama virtually knotted up in the race for the Democratic nod. On the Republican side, there is a consensus among those polls that McCain is becoming the strong favorite, with wide leads over Romney, Huckabee and Paul.
But it is important to remember that the delegate selection process is convoluted, particularly on the Democratic side, with allocations not reflected by the overall national vote totals. While the majority of delegates to the Republican National Convention are allotted on a winner-take-all basis by state or congressional district, the rules of the game are markedly different for Democrats.
The fact that Democratic Party rules mandate allocation of delegates in proportion to vote totals in states and congressional districts means that neither Clinton nor Obama is likely to emerge from Super Tuesday with a large overall lead in delegates.
Of the 1,688 pledged -- not super -- Democratic delegates at stake today, 1,078 -- 64 percent -- will be allocated proportionally within state subdivisions. In all but two states, these subdivisions are congressional districts; in New Jersey, delegates are apportioned within legislative districts. In Delaware, delegates are allotted within four local jurisdictions.
The vagaries of delegate allocation are such that the difference between 58-percent and 59-percent support in a six-delegate district would mean the difference between a three-to-three stalemate and a four-to-two win.
In other words, those junkies wishing to make remotely meaningful homemade calculations today would need to be armed with district maps, precinct-by-precinct election returns and a good calculator.
A district-by-district analysis prepared by the Cook Political Report's David Wasserman suggests that, based on demographic and socioeconomic performance in early states, an optimal Clinton outcome would be a 604 to 474 majority of district-level delegates in her favor, while an optimal Obama outcome would be a 586 to 492 lead in his favor.
If Clinton wishes to build a 50-delegate lead in this category, she would need her favorable scenarios to play out in 64 percent of districts.
On the other hand, if Obama wishes to build a 50-delegate lead, he would need his favorable scenarios to play out in 80 percent of districts.
Anthony Corrado and Tad Devine, two of the leading experts on the Democratic delegate selection process and veterans of past party delegate hunts, offered in a recent analysis that "these rules make it very difficult for a candidate, even a frontrunner, to build large delegate margins, especially in a race featuring two strong challengers."
They go on to predict a close delegate contest and raise the possibility that "super delegates" -- elected and party officials whose positions give them automatic seats at the convention -- could ultimately make the difference in the outcome.
Democrats are likely in for a wild ride.