Tensions about the immigration amendment process led to a particularly tense exchange on Tuesday, with “gang of eight” member Sen. John McCain questioning a fellow Republican who said the immigration bill wouldn’t secure the border.

The Arizona Republican accused freshman Nebraska Sen. Deb Fischer of making a “series of false statements” about the bill.

Following a lengthy floor statement in which Fischer criticized border security language in the Senate’s bipartisan immigration measure and contrasted it with an amendment she had written, McCain sought recognition for the purpose of what in Senate parlance is known as asking a question:

Like many Senate questions, McCain’s was designed as a retort. McCain asked Fischer whether she had ever visited the Arizona border with Mexico. She replied that she had been to the border between Texas and Mexico.

“I’d just say to the senator from Nebraska, she’s so ill-informed. The statement I just saw, I don’t know where to begin, except to say that if you don’t think that if this legislation secures the border, you haven’t spent any time on the border, certainly not any meaningful time,” McCain said. “I can’t express my disappointment in the series of false statements that the senator just made.”

Fischer responded: “I believe that my statement is correct. It reflects the values of my state, it reflects the values of those Americans, and it truly reflects their concerns with this piece of legislation that is before us now.”

McCain then invited Fischer to visit Arizona. The freshman from Nebraska said she would accept the invitation.

At day’s end Tuesday, the Senate had set a series of votes for late morning Wednesday that would be treated as though they had occurred at 1 a.m., allowing senators the chance to get a full night’s sleep before continuing the floor exchanges and amendment wrangling.

Considering the votes to have taken place at the wee hours of Wednesday morning preserves the timeline outlined at #WGDB earlier in the day.

Scott Campbell contributed to this report.