Republican Texas Sen. Ted Cruz is “perplexed” by GOP attacks on his effort to defund Obamacare and has no intention of backing down, despite complaints from other Senate Republicans that his crusade is not realistic and could potentially damage the party’s chances in the 2014 midterm elections.

“There may be people who lob attacks at him, but he’s not going to return those attacks,” Cruz spokeswoman Catherine Frazier told The Daily Caller, taking a firm stand in a battle that could determine the GOP’s strategic playbook heading into the 2014 midterms.

Cruz and fellow junior Republican senators Mike Lee and Marco Rubio are involved in a “coordinated effort,” according to Frazier, to urge Senate Minority Leader Mitch McConnell to block all continuing-resolution budget bills until Obamacare is defunded, either through budgetary means or by passing the Defund Obamacare Act, which has already failed three times in Congress.

Republican Sens. Bob Corker of Tennessee and Richard Burr of North Carolina strongly criticized the effort of Cruz and his two fellow junior senators, while Oklahoma Sen. Tom Coburn suggested that the plan’s political backlash could jeopardize Republican efforts to hold a majority in the House of Representatives next year.

“It’s a sideshow,” a Republican source on Capitol Hill told The Daily Caller. “We all know what’s going on. They’re just trying to drum up the base. That helps their donations, that helps their data collection.”

“Everyone [on the Republican side] opposes Obamacare, so why drum up this controversy? That does no one any good. It’s unproductive. The focus should be on the Democrats who voted it into law. It’s time for everyone to be on the same page,” said the source, who added that the political ambitions of Cruz, Rubio, and Lee are creating division in the Republican caucus, which allows media pundits to take sides.

Other Republicans are doubting the technical feasibility of the plan.

“Unfortunately, automatic spending that Democrats baked into Obamacare when the law was passed can’t be undone through a vote on government funding. The only way autopilot spending for Obamacare can be stopped is by repealing the law, and I will continue pursuing legislative efforts to do so,” New Hampshire Republican Sen. Kelly Ayotte said, disputing Cruz’s claim that Obamacare can be defunded in the fight over a continuing-resolution budget bill.

But Cruz is not backing down.

“We’re familiar with what others are saying out there,” Cruz spokeswoman Frazier told TheDC. “But [Cruz] and Senator Lee and Senator Rubio, they’re going to continue to get Americans engaged on this.”

“They believe that if Americans get engaged in this fight, we can pass a continuing resolution [that defunds Obamacare],” Frazier said. “We need to be taking every chance we have.”

The narrative pushed by rival Republicans that Cruz and his allies are aiming merely for public engagement and not for legislative success does not hold water, according to Frazier.

“Senator Lee has been working to spearhead this effort. Senator Lee had several other senators join him in writing a letter to Harry Reid,” Frazier said. “So they are making an argument to win over their colleagues.”

The conservative activist organization FreedomWorks strongly supports the effort by Cruz, Lee, and Rubio, even threatening moderate Republicans who might not get on board with the junior senators’ strategy.

“We agree with Lee: If you fund ObamaCare, you own it. If you are a Republican turning your back on any opportunity to dismantle ObamaCare before enrollment begins, you’d better have a good explanation for your constituents when they demand a town hall over August recess,” FreedomWorks said in a statement.

Cruz won 45 percent of the vote and the virtual presidential nomination in a 2016 conservative straw poll held at Colorado Christian University’s Western Conservative Summit, where he spoke this past weekend.

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