AUSTIN — After picking up 14 seats in the midterm elections, Democrats are using their increased numbers this session to derail key Republican priorities in a state where the left has long been out of power.

In flexing their political muscle, Democrats have blocked Gov. Greg Abbott’s embattled secretary of state nominee and helped stop a sales tax hike that GOP leaders had championed in order to cut property taxes.

"This session more than other sessions, the Democratic caucus has stuck together more. We’ve communicated a lot better,” said Senate Democratic Leader José Rodríguez of El Paso. "I think the midterm elections may have had something to do with the caucus being much more united."

Their wins, however, come thanks to unforced errors by Republican leaders, said Mark Jones, a Rice University political scientist.

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Before Abbott’s Secretary of State nominee David Whitley could be confirmed by the state Senate, Whitley’s office launched a flawed attempt to purge suspected noncitizens from the voter rolls. As a result, all 12 Senate Democrats lined up against Whitley’s confirmation, enough to block him from keeping the job beyond the legislative session’s end.

Abbott, Lt. Gov. Dan Patrick and House Speaker Dennis Bonnen’s plan to put the tax swap before voters as a constitutional amendment meant that it needed a steep two-thirds majority to pass — a hurdle that proved too high. In the House, at least 17 Democrats would have had to join every House Republican in backing the plan.

“The GOP set up Democrats to allow them to block it,” Jones said.

Republicans, however, say Democrats can’t take credit for undermining the tax swap. Houston Sen. Paul Bettencourt, a Republican who chairs the Property Tax Committee, became a vocal critic of the plan. And in private, some Republicans were grumbling about having to vote on raising the state sales tax to the highest in the nation, even though it meant decreasing property tax bills for their constituents.

An 11th-hour state analysis, showing the tax swap would have benefited business and the wealthy over middle- and low-income families, didn’t help. Ultimately, Senate Republicans pulled the tax swap out of a sweeping education bill, effectively dooming it.

“There were Republicans who had heartburn over it as well, just like the Democrats,” said state Rep. Dade Phelan, R-Beaumont. “And of course the Senate pulled it out as well.”

But already the state’s Democratic Party is wielding the now-dead sales tax hike as a campaign issue in Facebook ads. It comes as Democrats see an opening to seize control of the Texas House in 2020. They would need to flip at least nine more seats, but are targeting 18 Republicans in districts where Democrats lost last election by tight margins.

Meanwhile, Abbott, Bonnen and Patrick have pledged to stay the course on delivering property tax relief and upping public education spending.

“Speaker Bonnen believes it is in the House’s best interest to devote the limited time left in session to our Day One priorities — passing legislation to provide meaningful school finance and property tax reform for all Texans,” said spokeswoman Cait Meisenheimer in a statement. The session wraps up on Memorial Day.

It remains to be seen how Democrats — who have long prioritized increased public school funding and access to prekindergarten — will wield their power in the final weeks.

Republicans still have the numbers to pass bills Democrats oppose, including a proposal this week making it harder to remove historic and Confederate monuments from public land. But red meat issues — which dominated the last legislative session with sweeping the so-called bathroom bill that would have affected transgender Texans — are taking up less of the spotlight this session.

“I think elections have consequences,” said Rep. Celia Israel, D-Austin. “And because we had record turnout, it not only sent more Democrats here, but it sent a message to my Republican colleagues … They really want us to focus on mainstream issues.”