Obama has concentrated campaign cash and grass-roots muscle on a handful of caucus states, hoping that his enthusiastic, young supporters will turn out in large numbers. So look at the results from Kansas, his mother's native state and then the caucuses in Colorado, New Mexico, North Dakota and Minnesota. If If Obama does well in these caucus states it still could be a super Tuesday for him.

If the early bellwether states prove inconclusive for the Republicans, the night's winner most likely will be crowned in a cluster of Southern contests, except for Arkansas, which is Mike Huckabee territory. Outside Razorback territory, if Huckabee runs strong he'll take social conservative votes away from Romney, whereas a fading Huckabee could find Romney experiencing Southern Comfort and a possible upset victory to come in California. In which case, you better throw another bag of popcorn into the microwave.

Whatever happens tonight, the Democratic candidates already are making plans for the Texas and Ohio primaries on March 4.

"Many of us will be making our reservations for Texas and Ohio," said Clinton strategist Howard Wolfson, "and perhaps Pennsylvania (in April) and beyond that."