Sen. Lindsey Graham and the White House are in a war of words as lawmakers try to work across party lines and along Pennsylvania Avenue to try and find a deal to reopen the government.

Graham has been one of the main negotiators during the shutdown, which started early Saturday morning. He’s spent a lot of time shuttling between the offices of Sens. Mitch McConnell and Chuck Schumer, doing shuttle diplomacy between the leaders of Senate Republicans and Democrats.

As stressful as that role must be, it was a negotiator Graham has been working with in the White House — Stephen Miller — who he complained about to reporters on Capitol Hill Sunday.

“I've talked with the president. His heart is right on this issue. I think he's got a good understanding of what will sell,” Graham told reporters. “And every time we have a proposal it is only yanked back by staff members. As long as Stephen Miller is in charge of negotiating immigration, we are going nowhere. He has been an outlier for years. There's a deal to be had.”

Miller worked for many years as a top legislative aide to then-Sen. Jeff Sessions, working particularly hard on immigration. He’s now one of the top policy aides on immigration in Trump’s White House.

Graham’s comments prompted White House spokeswoman Hogan Gidley to fire back at a Republican who has become a friend to Trump during his time in office.

“As long as Sen. Graham chooses to support legislation that sides with people in this country illegally and unlawfully instead of our own American citizens, we’re going nowhere,” Gidley said.

“He’s been an outlier for years,” she added, turning Graham’s words about Miller back against him.

Graham and Democratic Sen. Dick Durbin, the second most powerful Democrat in the Senate, came to the White House earlier this month with a deal they believed would end up solving the legislative crisis precipitated by Trump deciding to end the Deferred Action for Childhood Arrivals program in September. That program is set to end on March 5, per Trump’s order.

Graham and Durbin came up with a deal formed by a bipartisan group of senators that would have kept DACA recipients in the country legally and added more funding for border security.

However, a White House official said the deal ended up being lacking in some very important ways that were unpalatable to Trump.

The official said the deal would not only have legalized DACA recipients but their parents as well — about 8 million people. Arkansas Sen. Tom Cotton said earlier Sunday that was unacceptable to immigration hardliners like himself in Congress and Trump felt the same way.

The deal would have also expanded chain migration and DACA recipients could have brought about 13 million extended family members to the country as immigrants, the official said.

Other concerns the White House had with the deal included questioning if legalizing the status of DACA recipients would encourage illegal immigration because there would be no punishment for coming to the country illegally; not adhering to the president’s desire to see more skilled immigrants coming to the U.S. instead of unskilled workers.

The White House official deemed it an “extremist proposal.”

Democrats were unwilling to move forward on a bill to fund the government for four more weeks without protections for DACA recipients Friday night, leading to a government shutdown that started at midnight Saturday.

Graham called the views held by some negotiators in the White House — not mentioning Miller by name, but clearly alluding to him hours after his statement to reporters — “extreme and unrealistic.”

“President Trump has expressed a desire to have border security with compassion on immigration. #winningcombination. General Kelly is tough but reasonable. Some other staff in the White House hold extreme and unrealistic views. They hold us back from getting a solution,” Graham tweeted.