Actually derailing the redistricting effort, which was one of nearly 20 items added to the special session agenda by Gov. Greg Abbott, would be a herculean lift fraught with risk for legislative Democrats. Delaying the process with a walkout would require strong participation by most of the party's caucus, and could carry steep financial costs.

President Donald Trump on Tuesday said a Texas redistricting plan ahead of the midterm elections should gain Republicans five seats in the U.S. House.