Texas has 228 total delegate votes - 126 district / 42 at large; 25 Pledged PLEOs; 32 Unpledged PLEOs; 3 Unpledged add-ons.
At the first level, only 126 of the 228 delegates to the Democratic National Convention are allocated based on the results of the voting in the Texas Presidential Primary. Even then, it is not based on state wide popular vote, but by Senatorial district. There are 31 state senatorial districts. Even then, it is not apportioned equally, but different districts get more or less delegates depending on how strongly they supported the democratic candidate for president in the last election. If you are a Democrat in a Republican dominated district, you will not get as many delegates. Sorry. There are prices to be paid. You can have as few a 2 and as many as 8 delegates in your district. Senate District 31 has 2 delegates. Senate District 14 has 8 delegates.
At the second level, on March 29, the County and Senate District Conventions select delegates to State Convention.
At the third level, on June 6-7, The State Convention will choose the remaining 67 pledged delegates. These 67 delegates are allocated to candidates based on the preference of the delegates at the State Convention as a whole.
There are 42 at-large National Convention delegates and 25 Pledged PLEOs. The remaining 35 National Convention delegates consist of:
32 Unpledged PLEO delegates:
17 Democratic National Committee members.
13 Members of Congress (0 Senators and 13 Representatives).
2 Distinguished Party Leaders (former House Speaker James C. Wright, Jr., former DNC chairman Robert Schwarz "Bob" Strauss).
3 Unpledged "add-on"s (elected at the state convention). These 35 delegates and will go to the Democratic National Convention officially "Unpledged".
Whew, there you have it. This is how you get your delegates in the Texas Democratic Party. It helps keep the unwashed masses from picking someone the leaders don't want.