The Texas Senate operates under rules and traditions that require 2/3rds of the Senators present to vote in favor of any bill coming to the floor for debate. Partisanship by both sides has put increasing strain on the 2/3rds tradition. Last session and this one an exception was made to the 2/3rds rule for the Voter ID bill, which only requires a majority vote. Tomorrow the 2/3rds tradition will shatter.
Senate rules state that bills will be taken up in the order they are reported from committee. At the beginning of each session, the Senate passes a "blocker" bill out of committee but never brings it to the floor. Therefore, every other Senate bill considered during the session is not in the regular order of business, and the Senate must suspend the rules with a 2/3rds vote to consider the bill.
Senate Rule 5.10 states that calendar Wednesday and Thursday are House bill days. Under the rule, House bills are taken up before Senate bills. HB 1, the budget, is the first House bill in the order and therefore the Senate does not need to suspend the rules to consider it. A simple majority of 16 Senators can vote to bring up the bill.
The Senate failed to suspend on the budget this evening by a party line 19 - 12 vote. Tomorrow, on House bill day, it will bring the budget back up and only need a simple majority or 16 votes to pass it to Third Reading. This is good news if you want to avoid a summer special session. It's bad news if you believe in the 2/3rds tradition of the Senate, because tomorrow partisanship by both sides will effectively end it.