Ted Cruz says his hard-line strategy to defund Planned Parenthood and risk a government shutdown is about doing the “right thing” and following through on Republicans' vows to conservative voters.

But many of his Republican colleagues say it’s really all about Cruz.

Even some of his closest allies from past battles— fellow tried and true tea party Republicans like Sen. Mike Lee of Utah — aren’t exactly jumping to join Cruz’s latest crusade. Same goes for Cruz’s onetime allies-turned-presidential rivals, Sens. Marco Rubio of Florida and Rand Paul of Kentucky.

As the Texas Republican prepares for a potentially decisive month in his presidential campaign with his high-profile Planned Parenthood push, his colleagues in the Senate are more agitated with him than ever. The effort, they say, carries more than a whiff of his losing strategy to defund Obamacare in 2013 — which culminated in a government shutdown, damaged the GOP’s political standing and left the health care law unscathed.

“I don’t want to use a failed tactic for political purposes knowing that it’s not going to succeed,” said Sen. Dan Coats (R-Ind.). “It will certainly get Sen. Cruz a lot of attention, which is obviously something that anybody running for president would want to get.”

Republicans now have the majority and nine more senators than in 2013, but Cruz hasn’t yet been able to capitalize on that position of strength. He called Senate Majority Leader Mitch McConnell (R-Ky.) a liar in July and is determined to dash any hopes the GOP leader might have had of a turbulence-free September. 

But his efforts to recruit other Republican senators to join him isn’t going smoothly. Cruz is circulating a letter among senators hoping to get them to sign on to his vow to oppose any bill that funds Planned Parenthood this month, but his colleagues aren't biting.

In an interview, Sen. Kelly Ayotte (R-N.H.) said it’s “obvious” Cruz is only making this his latest cause to boost his visibility in a presidential campaign. And Ayotte, who withdrew her name from Lee’s 2013 letter on Obamacare, said she will “absolutely not” sign onto Cruz’s latest missive.

“There are not enough votes to even get (to) 60 in the Senate. But even if you could get by that (hurdle), the president is going to veto it and we certainly don’t have 67 votes,” Ayotte said. “So I guess I would ask: What’s the strategy for success?”

Whereas in late August of 2013, Lee had secured pledges from 14 senators to defund Obamacare in the spending bill, Cruz is just getting started on his lobbying effort. But Lee, a frequent Cruz ally, hasn’t yet signed on, and conservative Sens. Jim Risch of Idaho and Deb Fischer of Nebraska, who jumped into the Obamacare fight, are keeping their powder dry this time. 

Long-shot presidential candidate Sen. Lindsey Graham (R-S.C.) said the only way Planned Parenthood will lose its funding is if President Graham is in office to sign such a bill into law. 

Cruz wouldn’t say Wednesday how many co-signers he has, and neither his office nor conservative groups tracking the debate could come up with a number in the Senate to match the 28 House members who have adopted Cruz’s position. The conservative senator said the letter is merely “designed to put down a marker and start a conversation” and dismissed colleagues who said he only takes such hard lines to draw attention to his presidential campaign.

“In Washington those that want to do nothing always blame the pressure to deliver results on politics,” Cruz said.

The forceful response to a series of graphic Planned Parenthood videos allegedly showing executives discussing the sale of fetal tissue is part of Cruz’s attempt to be the only real anti-Washington candidate who happens to work in Washington. He’s challenged McConnell in personal terms and taken hard lines on conservative causes from opposing the Iran nuclear deal to confirming a new attorney general. Often, when his colleagues disagree with him, he uses that friction to augment his positioning as a Beltway outsider and to raise money. 

But Cruz also has a knack for having the pulse of the party’s right flank. He meets frequently with House conservatives and often stakes out tough stands before anyone else. While the majority of the dozen-plus senators interviewed for this story said they won't sign on to Cruz’s letter, others weren’t as quick to dismiss it.

“I’ll give him the benefit of the doubt before I say yes or no,” said Sen. Mike Rounds (R-S.D.). 

Senior Republican sources say that most senators are treating Cruz like “kryptonite” after his verbal attacks on McConnell and the poor returns from the 2013 Obamacare fight. They say McConnell hasn’t even had to ask Republican senators to hold off on Cruz’s effort, partly in disagreement with the tactics but more because of who's devising them. 

“Probably more the messenger than the strategy,” said one Republican senator.

Cruz’s strategy is even dividing social conservatives, who are trying to tap into discontent with Planned Parenthood to build support for a bill that would federally ban abortions after 20 weeks of pregnancy. While Heritage Action is strongly behind Cruz’s plan, the National Right to Life Coalition has thrown cold water on the strategy and Susan B. Anthony List has declined to explicitly bless it.

“I am for any method that would actually defund Planned Parenthood. I am for any strategy that would do it,” said SBA List President Marjorie Dannenfelser. According to the Congressional Research Service, shutting down the government would actually keep most funds flowing to Planned Parenthood. 

Though they aren’t taking the same hard line, a group of social conservatives including Dannenfelser wrote House leaders this month to urge them to attach legislation defunding Planned Parenthood to a “must-pass” spending bill. Notably, they do not say they will oppose a spending bill that does fund Planned Parenthood, as Cruz prefers.

GOP leaders may not like Cruz's tactics but know they're still in a fix. It's unclear how they will get Republicans to vote for a spending bill that funds Planned Parenthood, and Senate Democrats reiterated on Wednesday they won’t vote for a bill that would block money from going to the organization.

Republican leaders are discussing several strategies, including continuing investigations of Planned Parenthood and holding a separate vote on defunding Planned Parenthood that wouldn't risk a shutdown (one such vote already failed in the Senate). 

Cruz says he won’t stand for that.

“The right answer here is not the Washington solution of a meaningless show vote. ‘Let’s have a meaningless vote, let’s appoint a commission, let’s gaze at our navels.’ That’s not the solution that makes sense,” Cruz said. “We should not be spending taxpayer funds to fund an ongoing criminal enterprise.”

But many Republicans say it’s Cruz’s plan that makes no sense. The endgame may be a shutdown, for which the GOP majority would shoulder much of the blame, according to early polling. 

“Let’s pass protection of life 20 weeks and after. That would be a reasonable response here,” said Sen. Ron Johnson (R-Wis.). “Develop a winning strategy rather than one that’s guaranteed to lose.”

The feeling that Cruz’s strategy is a political loser is directly related to the Senate GOP’s fragile majority. The party is defending 24 seats in 2016, and vulnerable lawmakers like Ayotte and Johnson don’t want the word “shutdown” anywhere near their names. 

Not to worry, Cruz says: This time it would all be on President Barack Obama if government funding lapses.

“President Obama has embraced the radical position ... to try to shut down the entire federal government if this one private organization does not get taxpayer money,” Cruz said. “It is only in the twisted, inverted logic of the Washington Beltway that anyone other than Barack Obama would bear responsibility for that shutdown.”