The popularity of Texas Gov. Greg Abbott could help Sen. Ted Cruz in his bruising re-election battle.

Abbott signed a law that would eliminate straight-ticket voting in the Lone Star state in 2020 – but this year he’s been urging Republicans to vote along party lines – which could give Cruz a major boost.

“Abbott is focused on supporting the entire Republican ticket and encouraging straight-ticket voting,” said Mark Jones, a political science fellow at Rice University’s Baker Institute, “which means if Cruz wins by a very small number – say 2, 3, 4, 5 percent, he may in respects owe his re-election to Gov. Greg Abbott.”

Texas is one of eight states that allow voters to choose all candidates of a party with a single-ballot mark. Jones said the practice could help Cruz, who’s locked in an unexpectedly close race with Democratic challenger, Congressman Beto O’Rourke. Recent polls show the Republican incumbent maintains a single-digit lead over O’Rourke.

Several Texas counties saw record turnout for the first day of early voting. The enthusiasm could help candidates down the ballot. (Fox News )

But some doubt that Abbott will make a difference.

“I think Cruz is running his own race. I really don’t see Abbott’s popularity crossing over to help Cruz,” said Holly Turner, a Republican strategist and partner for Stampede Consulting. “I think anyone that goes in to vote for Abbott is probably going to be a Cruz supporter, as well.”

Straight-ticket voting came under fire last week after early voters complained that when they cast straight-ticket ballots, voting machines in at least 80 counties flipped their votes in key races, including the competition between Cruz and O’Rourke. Some voters said Cruz’s name was selected despite choosing Democrats down the ticket and intending to vote for O’Rourke.

TEXAS VOTERS CASTING EARLY BALLOTS CLAIM VOTING MACHINES ARE SWITCHING THEIR BALLOT CHOICES

A spokesman for Secretary of State Roland Pablos blamed user-error, attributing the mistake to “voters hitting a button or using the selection wheel before the screen is finished rendering.”

Still, Republicans and Democrats believe straight-ticket voting will help candidates down the ballot, especially those in judicial races.

“What you have is the Beto O’Rourke umbrella talking to all of those grassroots activists who they need to get out to vote when that local congressional race or that local State [House] race may not have the finances to actually go out and ask that person to show up and vote,” said Chuck Rocha, Democratic strategist and president of Solidarity Strategies.

Political experts say the Senate race between Republican incumbent Senator Ted Cruz and his Democratic challenger, Congressman Beto O'Rourke is the driving force this midterm election. (Fox News )

Small races rely on larger ones to lift the party, experts say.

“So, if their party is doing well,” Turner said, “then they're going to do well.”

More than 60 percent of voters chose the straight-ticket option in 2016, according to an analysis from Austin Community College’s Center for Public Policy and Political Studies. Experts say the practice generally benefits Republicans statewide.

“The big thing in the Senate race between O’Rourke and Cruz is turn-out, and Republicans have done a better job in Texas, and that’s why it’s still a red state,” said Bob Cusack, editor-in-chief at The Hill in Washington, D.C.

The option could spell trouble for some candidates, especially for those in the 32nd, 23rd, and 7th districts, areas that Hillary Clinton won in 2016.

“They have got to be nervous that a lot of those Democrats are going to show up because of O’Rourke, and they’re going to be voting Democrat, Democrat, Democrat,” said Cusack.

Straight-ticket voting ends in 2020, which has drawn mixed reactions from Republicans and Democrats. (Fox News )

Some have praised Abbott’s decision to eliminate straight-ticket voting in 2020, saying it decreases partisanship in the voting process.

“I think it’s important for voters to get to know who they’re voting for. I think them having the opportunity to make an educated choice is going to be good for the state of Texas,” Turner said.

Still, others say without the option, voters will inevitably see longer lines at the polls, which could deter them from voting. Rocha thinks Democrats, who overwhelmingly vote straight ticket, could take a hit.

“The ballot stays the same. You can still make all the informed decisions and go from Democrat to Republican down that ballot. All we’re saying is leave the straight-ticket bubble for both parties,” he said. “If you’re in a hurry, you lock all the Democrats, you only have to circle in one bubble. It don’t cost you nothing.”