(CBSNews.com) - Sen. Ted Cruz, R-Texas, acknowledged Sunday that his push to defund Obamacare - even if it means shutting down the federal government in the process - still lacks the votes to succeed in the Senate.
"We do not have the votes right now," he said on CNN. "We need 41 Republicans in the Senate or we need 218 Republicans in the House." And to reach that threshold, Cruz admitted, it will take a "grassroots tsunami" pushing legislators to stand strong against the health-care reform law, come what may.
The current resolution funding the government expires at the end of September. Some Republicans, including Cruz and Sen. Marco Rubio, R-Fla., have urged Republicans to use that deadline as a pressure point, passing a law funding the government without Obamacare and daring the president to use his veto pen.
Other Republicans, however, have said that Obama would never sign a funding bill that omitted his signature domestic achievement, warning that the resultant shutdown would damage the GOP politically and do almost nothing to undermine the health-care law.
Cruz, mindful of the skeptics, sketched out his legislative game plan, casting doubt on suggestions that a shutdown would hurt Republicans.
"The House of Representatives should pass a continuing resolution that funds the federal government in its entirety, every aspect of the federal government, except Obamacare," he said. "Now, the next stage, we know how this play goes forward. President Obama and Harry Reid will scream and holler that the mean nasty Republicans are threatening to shut down the government. "
"And at that point, Republicans have to do something we haven't done in a long time - stand up and win the argument," he explained. "We have to stand up and say, 'No, we want to keep the government open. We have voted to keep the government open, to fund the government. Why is President Obama threatening to shut the government down, to force Obamacare down...the throats of the American people?'"
When CNN's Candy Crowley pointed out that Obamacare was the law of the land - "You lost," she told Cruz - the Texas freshman was defiant.
"It's not working and it's hurting Americans," he insisted, saying he's "not at all" convinced Obama would veto a continuing resolution defunding Obamacare.
Former Sen. Scott Brown, R-Mass., who hails from the moderate wing of the GOP, was not convinced that Republicans could avoid being scalded by a shutdown fight, telling "Fox News Sunday" that a shutdown is "exactly" what Democrats want.
"That will just show, 'Oh, here we go again!'" he explained, anticipating the Democratic response: "The Republicans are holding everything up. You're not going to get your paycheck."
"They're going to throw it on us," Brown predicted.
Gov. Bobby Jindal, R-La, said on NBC's "Meet the Press" that a government shutdown would probably not be necessary, but he counseled congressional Republicans not to "take any option off the table."
"I don't think this president or the Democrats are going to want to shut down the government. That's a false choice. That's a threat coming from them," he said. "I don't think you have to shut down the government to repeal and replace Obamacare. But I don't think Republicans should be taking options off the table. I think we should be fighting to defund it."
Whichever game plan Republicans decide upon, they'll have precious little time to put it into action: When Congress returns from its recess in September, lawmakers will have only nine days in session to broker a compromise before the government runs out of money.
© 2013 CBS Interactive Inc. All Rights Reserved.