*This story has been updated throughout. 

Texas Democrats maintained their 16-year losing streak on Tuesday night, with Republicans decisively sweeping all 15 statewide races on the ballot.

Republicans were poised late Tuesday night to win all of the statewide races by more than 20 percentage points, despite tens of millions of dollars spent on high-profile yet ineffective Democratic campaigns, including Wendy Davis' bid for governor and Leticia Van de Putte's race for lieutenant governor. Texans have not elected a Democrat to statewide office since 1994.

The wins for the GOP included Republican George P. Bush — the Bush family heir who is widely expected to seek higher office in four years. Bush easily won his bid for land commissioner against Democrat John Cook, a former El Paso mayor.

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"This is the future of our state," Bush said in his victory speech. "It's a conservative future and it is here now. The people of Texas have rallied around a common set of beliefs. We believe in freedom, we believe in family and we believe in faith."

Among the statewide candidates, U.S. Sen. John Cornyn had the most commanding lead, defeating Democrat David Alameel by around 30 percentage points.

“I think the results show that Democrats still have a long way to go in Texas before we can talk about the state turning purple, much less blue," Alameel said in a statement. "First, our state party needs to do some serious soul-searching."

Democrats put up candidates in 12 of the 15 statewide races on the ballot. That included some down-ballot races in which they held out hope that the Republican candidate was vulnerable to a spirited challenge.

In the race to replace Greg Abbott as attorney general, Republican Ken Paxton trounced Democrat Sam Houston. Houston had tried to draw attention to his fledgling campaign by hammering Paxton on reports that Paxton had violated state securities law. The Texas State Securities Board fined Paxton $1,000 for failing to report he had acted as the unregistered representative of an investment adviser.

Republican Glenn Hegar was also comfortably ahead in his bid to succeed Comptroller Susan Combs. Hegar was leading Democrat Mike Collier 59 percent to 37 percent.

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“As the next comptroller, I will not forget who my bosses are – hard-working taxpayers from across the state – and the duty they elected me to fulfill,” Hegar said in a statement. “Together, we will continue to stand up for the principles we believe in by making government more efficient, eliminating wasteful spending and putting more money back into the pockets of taxpayers.”

Collier, a certified public accountant from Houston, ran one of the most aggressive campaigns among Democrats this year, going on television with ads earlier than most other candidates in the state and mocking Hegar’s background as a farmer in an online video that drew more than 36,000 views.

Sid Miller, the former Republican state representative, had no trouble clinching his race for agriculture commissioner against Democrat Jim Hogan, who made headlines for investing virtually no time or money into his race. Despite the race he ran, Hogan managed to draw a share of the vote comparable to other statewide Democrats on the ballot

Ryan Sitton, a mechanical engineer from the Houston area, cruised to victory over Democrat Steve Brown in the race for an open seat on the Texas Railroad Commission – the three-member panel that regulates oil and gas production. Sitton, who has touted his industry experience, will help oversee an oil and gas boom unseen in 30 years, and some of the environmental and property rights squabbles it has spurred.

In an email blast to supporters, Sitton said he would do “everything in my power to make sure that Texas responsibly produces as much energy as we possibly can.”

“With the right policies in place,” he added, “the massive growth in our energy production will continue, securing our national security, economic and geopolitical interests.”

All the Republicans in the statewide court races won handily, and led Democrats by at least 20 points. Larry Meyers, a judge on the statewide Court of Criminal Appeals who switched parties from Republican to Democrat in December 2013, lost his bid to unseat Republican Jeff Brown on the Texas Supreme Court. Meyers was elected to the statewide Court of Criminal Appeals as a Republican in 1992.

Bobby Blanchard, Neena Satija and Jim Malewitz contributed to this story.