NASHVILLE — A new poll released Sunday shows Donald Trump leading the pack among likely Republican voters in Tennessee, even as another member of the state's GOP establishment lined up behind Florida Sen. Marco Rubio.

U.S. Sen. Lamar Alexander, R-Tenn., has endorsed Rubio and plans to appear with him and Gov. Bill Haslam, who endorsed Rubio last week and is appearing in an ad for him.

The NBC News/Wall Street Journal/Marist polls released in advance of Super Tuesday primaries favored Trump, who appeared before a cheering throng Saturday near Memphis.

The billionare and reality TV star had 40 percent of the vote compared to 22 percent for his nearest rival, Texas Sen. Ted Cruz, and 19 percent for Rubio. But the Republican contest is much tighter in Georgia, according to the polls.

Retired neurosurgeon Ben Carson had 9 percent while Ohio Gov. John Kasich, who appeared in Nashville on Saturday, ranked at the bottom with 6 percent.

The poll of 665 likely GOP primary voters conducted earlier this month had a margin of error of plus or minus 3.8 percent.

Democrat Hillary Clinton, meanwhile, held 2-to-1 leads in both Tennessee and Georgia over U.S. Sen. Bernie Sanders, the democratic socialist from Vermont. The poll involved 405 likely Democratic voters and had a 4.9 percent plus or minus margin of error. It was conducted before Clinton's blowout Saturday in South Carolina's Democratic primary.

A total of 2,167 registered Tennessee voters were surveyed and Trump and Clinton led by somewhat similar margins among potential Republican and Democratic primary voters.

In Georgia, Trump drew support from 30 percent of the 543 likely GOP primary voters surveyed. Cruz and Rubio tied at 23 percent and Carson and Kasich tied at 9 percent. That portion of the poll had a margin of error of plus or minus 4.2 percent.

Clinton had 64 percent to Sanders' 30 percent among the 461 likely Democratic voters surveyed in Georgia. That's slightly better than a 2-to-1 margin. The margin of error in the Democratic portion of the Georgia poll was 4.6 percent.

A third survey from NBC News/Wall Street Journal/Marist was devoted to Texas, where Cruz led Trump by 39-26 percent among likely GOP primary voters. Rubio had 16 percent, Carson drew 8 percent and Kasich had 6 percent support.

The NBC News/Wall Street Journal/Marist surveys in all three states were conducted before Thursday's harsh debate, in which Rubio and Cruz repeatedly attacked front-runner Trump.

The organizations resurveyed 30 percent of the samples in all three states and found little movement, although those re-surveyed thought Rubio won the debate.

Haslam came out for Rubio last week, releasing a statement and appearing in an ad.

"Marco Rubio is the conservative candidate who can inspire us, win the election, and lead our country," Haslam said in the statement released by the Rubio campaign. "The stakes are high. If our nominee does not win, Hillary Clinton's justices will control the Supreme Court for 30 years and we'll be stuck with Obamacare forever."

On Sunday, Alexander's statement said that he has "watched Marco up close."

"I have seen him take the lead in passing new laws to impose tough new sanctions on Hezbollah terrorists, and to get rid of incompetent managers who weren't doing their jobs to help veterans," Tennessee's senior senator said.

Alexander said Rubio also has proposed "good new ideas for giving students more options for college. I am convinced he would be a strong and effective president of the United States."

Both the Alexander and Haslam endorsements came after early voting ended in Tennessee, where some GOP operatives believe as many as 30 percent of Republicans have already voted.

Contact staff writer Andy Sher at asher@timesfreepress.com or 615-255-0550. Follow him on Twitter at AndySher1.