Talking to a small group of reporters Wednesday, Sen. John McCain struggled to be heard over the booming voice of Sen. Ted Cruz, who yards away had assumed the stakeout position usually reserved for leaders in the Capitol’s Ohio Clock Corridor.

Cruz was railing on Senate Republican leadership, on the president’s health care law and on the “establishment,” in front of a swarm of reporters. Cruz’s words rang like a triumphant victory speech, even though his strategy to link defunding of the Affordable Care Act to funding the government had failed. In the shadows of cameras trained on the Texas Republican, McCain, a 26-year Senate veteran, was peeved and a touch incredulous as to how this debacle played out for his party.

“That’s fine. He’s entitled to that,” the Arizona Republican said, when asked about the impromptu Cruz news conference in front of him.

McCain then quickly shifted to praising a bipartisan group of 14 senators, led by Maine Republican Susan Collins, who served as a catalyst for the agreement leaders eventually brokered. “There are 14 of us who have already joined together. Many more wanted to join that group — a lot more — so there’s a real impetus to prevent this from happening again and for us to work together,” McCain said. “I hope we have learned … in 1995, we learned a lesson then, hopefully it will be another decade or so until we try this again.”

But there is residual fear from aides in both parties that it won’t be 10 years before another standoff, that the conservative faction mobilized by Cruz (especially in the House) won’t be moved by recent polls showing a huge hit to the Republican brand, and that, perhaps most dangerously for GOP leaders, Cruz and his acolytes won’t care. Asked time and again whether they were concerned that Cruz would draw a similar line in the sand in the months ahead when it comes time to fund the government and pay its bills again, multiple senators demurred or laughed nervously. They’ve seen this show before.

Cruz is the Senate heir apparent to former senator and current Heritage Foundation President Jim DeMint, a man who once famously said of a moderate colleague who later was forced out of the party: “I’d rather have 40 Marco Rubios than 60 Arlen Specters, and the reason for that is if you want 60 Republicans, you’ve got to have at least 40 to start with who stand on principle.”

Cruz has starred in ads for DeMint’s former PAC, the Senate Conservatives Fund, which is actively campaigning against incumbent Republicans, and so these past two weeks have only expedited the process of his falling out of favor with many colleagues.

The question is whether the Republicans who pushed this deal to reopen a government shuttered for more than two weeks have the strength to resist Cruz if he pushes a similar strategy again.

“We have larger constituencies to answer to — a whole state,” Sen. Lindsey Graham said of the differences between Senate Republicans and the House members led by Cruz. “You know, I’ve got a primary, but I care about the party, not just my place in the party. I care about how many Republicans are up here, not just the fact that I am one of them.”

The South Carolina Republican easily could have been one of the members pressured by his right flank. He has a challenger this cycle and made brief moves that underscored that. (He came out in favor of an amendment sponsored by Sen. David Vitter that would have revoked congressional staffers’ employer contributions to their health care, for example.) But on par he seems to be more a leader of a growing group of Republicans fighting against the tea party machine than he does a resigned participant in it.

“The question is, how do you handle that pressure [from outside conservative groups]? I’m not mad at a group wanting their way. I am trying to focus all the Republican Party to chart a better way,” Graham said. “The way we’re behaving and the path we’ve taken over the past couple of weeks leads to a marginalized party in the eyes of the American people, a form of conservatism that is probably beyond what the market would bear. It has been the best two weeks for the Democratic Party in recent times because they were out of the spotlight and didn’t have to showcase their ideas. They do poorly when the spotlight’s on them. Apparently we do poorly when the spotlight’s on us.”

Republican senators such as Bob Corker of Tennessee and Tom Coburn of Oklahoma have pushed back on the Cruzification of Congress by arguing that forcing a shutdown over the health care law has detracted from the GOP’s message of reining in spending. Many of their colleagues were frustrated by the strategy and the tanking in the polls, even if Cruz did bring in his own pollster to a conference meeting last week to try to calm their nerves.

For now, Senate Republicans who overcame Cruz and jammed House conservatives seem to be holding their collective breath.