Portman’s amendment — which is cosponsored by Sen. Jon TesterJonathan (Jon) TesterFive things to know about Sanders’s single-payer plan Where Dems stand on Sanders's single-payer bill Overnight Regulation: DeVos ignites backlash with rewrite of campus sexual assault policy l EPA power plant rule decision likely this fall | Panel approves Trump financial regulator nominees MORE (D-Mont.) — would have strengthened the requirements for businesses to use an e-verify system to prevent illegal workers from being hired in the United States. He said it was necessary in order for the immigration reform bill to truly deter the illegal immigration flow.

“I don’t think this bill will work unless there is strong workplace enforcement,“ Portman said. “I’m not going to vote for it unless it has stronger enforcement because I don’t think you’ll be able to stop the flows of illegal immigration without it.”

Moments before McCain’s remarks, Senate Majority Leader Harry ReidHarry ReidThe Memo: Trump pulls off a stone-cold stunner The Memo: Ending DACA a risky move for Trump Manchin pressed from both sides in reelection fight MORE (D-Nev.) tried to set up votes on 32 amendments — 16 of which were from Republicans, including Portman’s — but Sen. Chuck GrassleyCharles (Chuck) Ernest GrassleyGrassley: 'Good chance' Senate panel will consider bills to protect Mueller Overnight Finance: CBO to release limited analysis of ObamaCare repeal bill | DOJ investigates Equifax stock sales | House weighs tougher rules for banks dealing with North Korea GOP state lawmakers meet to plan possible constitutional convention MORE (R-Iowa) objected saying the amendment process had not been as "fair and open" as promised.

"The majority party has offered an agreement that in our view is insufficient," Grassley said. "I feel a bit used and abused in this process for 2.5 weeks we’ve been pushing to get votes on our amendments. We’ve had a measly 10 votes on amendments.

"I’m still willing to negotiate votes, but it will need to be a lot of votes. … In the end we may very well not be having anymore amendments."

Portman said he was willing to work through the weekend to add his amendment and finish work on the immigration reform bill, which is expected to pass on Friday.

Reid said Portman had the opportunity to add his amendment to the bill when lawmakers were negotiating other changes in the substitute amendment that included the "border security surge" measures — which passed today on a 69-29 vote — but Portman said no.

"I have been very patient today, but I have had it," Reid said. "He had the opportunity to have this amendment in the bill as offered, but I have had it today — this is enough. He had the right to put it in the bill, he said no. I assume it’s because he wanted some big show out here today, but I have had enough.”