Early voting is underway on whether to tap the state's rainy day fund to create a $2 billion water infrastructure fund.
But while the constitutional amendment enjoys widespread support, there is vocal conservative opposition that could derail it in a low-turnout election.
Listed on the ballot as Proposition 6, the measure would allow the state to use the money to buy down the cost of bond financing for massive water development projects.
Gov. Rick Perry, House Speaker Joe Straus, and dozens of business and environmental groups support creating the State Water Infrastructure Fund.
Conservative activists Empower Texans and Longview Rep. David Simpson, a top tea party leader in the Legislature, is urging voters to oppose Proposition 6 because he believes the money will be used to distort the bond market.