U.S. Sen. Ted Cruz said Saturday that the GOP lost the government shutdown budget battle because some congressional Republicans turned on others, but that he doesn't think they will make the same mistake during the next political impasse.

"I am hopeful that in the future the Senate will listen," Cruz, the tea party favorite and freshman senator from Texas, told a convention in Austin of the Texas Medical Association.

Cruz staged a more than 21-hour quasi-filibuster in the Senate late last month, helping spark a budget fight in the Republican-led House that partially shuttered the government in an attempt to sever funding for the nation's new health care law.

Then, with the country facing a debt default, leaders in the Democratic-led Senate brokered a deal to end the standoff _ which Cruz dismissed as "selling the American people down the river."

"You don't win a fight when your own team is firing cannons at the people who are standing up and leading, which are the House Republicans," he said.

The deal sets up the potential for another budget showdown in January. Senate GOP leaders, however, have suggested that there won't be a repeat of the shutdown or a potential default crisis like in recent weeks.

But addressing reporters after his speech, Cruz would not say that another fight won't be coming.

"There will be plenty of time to consider the particular practical or strategic decisions," he said.

Asked if he was worried about retaliation from more-senior Republican leaders in the Senate, Cruz said, "I try very hard not to worry about the politics and the internal back-and-forth in Washington."

Many attendees gave Cruz a standing ovation at the end of his speech.

Some political observers now see Cruz as Texas' most popular Republican. But his approval ratings across the country may be slipping.

National polls have shown that while Americans in general don't love the health care law, they oppose defunding it _ especially if it means shutting down the government. And many of Cruz's Senate colleagues have bemoaned the shutdown for tarnishing the GOP's image.

Cruz also took questions from the audience and was asked if ideology driving Washington could outweigh political pragmatism.

"The arguments I have laid out today have not been ideological," Cruz said. "These were the essence of practical."