Republicans have lost their 102-member supermajority in the Texas House, opening the door for Democrats to slow or block the majority's conservative agenda.
Democrats have won more than 50 seats in the 150-member lower chamber of the Legislature. That means Republicans can no longer suspend the rules to push through legislation over the objections of minority Democrats.
Last year, Republicans had enough lawmakers to form a quorum without any Democrat showing up for work.
Democratic leaders have said they will use their increased strength to block conservative bills and demand compromise on public education and health care issues.
Republican lawmakers point out that they remain the majority party and will continue to demand less government spending and lower taxes.