Freshman Sen. Ted Cruz, R-Texas, suggested to Sen. John McCain, R-Ariz., that he no longer represents the majority of Senate Republicans on the issue of increasing the debt ceiling — and he offered a bet to prove it.

“There may be more ‘wacko birds’ in the Senate than is suspected,” Cruz said on the Senate floor, recalling the name that McCain once applied to Cruz and Sen. Rand Paul, R-Ky., after their talking filibuster against President Obama’s drone policy.

To test the hypothesis, Cruz suggested that McCain circulate a letter to the GOP conference stating that Republicans support allowing Senate Democrats to raise the debt limit with a simple majority.

“I believe he will find that his representation to this body, that it is only a minority of Republicans that oppose, that is not accurate,” Cruz said.

The Texas lawmaker offered McCain a bet: If McCain gets a majority of the GOP conference to sign such a letter, “I will offer here and now to go to a home game of my Houston Astros wearing an Arizona Diamondbacks hat,” Cruz said. “But I stand in complete comfort that I will not find myself in that situation because I don’t believe it’s a right that a majority of Republicans in this body have given up the fight on spending.”

McCain attacked Cruz’s position two days ago. “For four years, four years, we complained about the fact that the majority leader … would refuse to bring a budget to the floor of the United States Senate,” McCain said on the floor. “What [do] we on my side of the aisle keep doing? We don’t want a budget unless — unless — we put requirements on the conferees that are absolutely out of line and unprecedented.”

Sen. Mike Lee, R-Utah, explained why he, Cruz and Paul oppose going to conference unless Senate Democrats promise they won’t use the conference as a vehicle to raise the debt ceiling.

“We want a very simple assurance that any conference report that results from this conference will not be used to raise the debt limit,” Lee said on Tuesday. “We want some assurances that this important decision will be made under the regular order of the Senate — that the normal rules of the Senate will apply to this, that this won’t be negotiated behind closed doors in a backroom deal.”