by Howard Witt

So you thought the Democratic presidential picture was going to get a bit clearer on Tuesday night? Good luck with that in Texas.

Here’s a quickie 10-point primer on how the convoluted “Texas Two-Step” primary is going to work—and why the results are likely to be neither timely nor definitive on Tuesday night.

1 - Texas will send a total of 228 delegates to the Democratic Convention. But only about half of them will be determined on Tuesday.

2 - 35 of those delegates are unpledged "super" delegates, so they will join the Great Unknown Super Delegate Muddle.

3 - 126 delegates will be allocated directly based on the results of the primary vote in 31 state Senate districts across Texas. But not all of those Senate districts are created equal: Their delegate richness is determined by the level of Democratic turnout in recent elections. This means that Senate districts in and around major metro areas (Houston, Dallas, Austin), where Obama is expected to do well, have more delegates on offer than Senate districts in predominately Hispanic south Texas, where Clinton is expecting to dominate. The delegates will be distributed proportionately in each district based on the votes cast for each candidate, meaning that a close contest in a district might mean a difference of only 1 delegate for either candidate. Here is a map showing the delegate allocations by Senate district:

4 - The polls close across Texas at 7pm local time. Most of Texas is in the central time zone, with the exception of some west Texas areas (e.g. El Paso) which are in the mountain time zone. The Texas secretary of state's office says it will begin reporting results immediately after 7pm central time. These results will be available at http://enr.sos.state.tx.us/enr/

5 - Another 67 delegates (42 at-large and 25 super delegates) will be allocated according to the results of a three-month-long series of local, regional and statewide caucuses. This caucus process begins on Tuesday night immediately after the polls close, when each precinct holds a caucus event.

6 - These precinct caucuses send delegates to county/district caucuses on March 29, which are followed by a statewide convention on June 6-7. It is only at the statewide convention that delegates are finally allocated to each candidate. And just to make things really interesting, delegates are not bound by their allegiances from the precinct and county caucuses.

7 - That means the precinct caucus results on Tuesday night will at best be a rough snapshot of support for Clinton and Obama, but in no way can those results be used to accurately predict how many caucus-chosen delegates each candidate will end up with.

8 - The precinct caucuses are predicted to take from 1-2 hours to complete. But the process is likely to be chaotic and it could take much longer. Both the Clinton and Obama campaigns have been frantically training precinct captains across the state to try to seize control of each caucus.

9 - The only source for preliminary precinct caucus results will be the Texas Democratic Party; the secretary of state's office is not involved because it's strictly a party function. The Texas Democratic Party says it will post those results on its website, http://www.txdemocrats.org, but the website is hard to reach in the best of times and it’s likely to be overwhelmed on Tuesday night.

10 - The Republican results will be much more straightforward, as there is no caucus event, and they will also be posted on the Texas secretary of state site.