WASHINGTON – You might assume a government shutdown that is about to set an unwelcome record and is being battled over funding for a border wall most Americans oppose might leave President Donald Trump itching to make a deal.

You would be wrong.

In a combative exchange with reporters Thursday as he left the White House for a day trip to Texas, wearing a campaign "Make America Great Again" hat, Trump denounced as dishonorable the Democratic leaders who would have to negotiate any agreement. He accused his opponents of not caring about violent crime and national security. Although he said the word "compromise," he gave no indication that he was actually willing to give an inch on his demand for funding the wall.

Trump attributes his spectacular rise in politics to the shrewdness of his gut, the power of his bluster and his command of a devoted core of supporters. Even though those are the instincts that led him into an impasse with no clear exit, they are still the priorities he extols.

He bragged not about progress toward resolving the standoff but about the unity of Republicans behind him in standing firm, although a few GOP senators have expressed concern about the extended shutdown. It is poised to become the longest in history on Saturday. "They all want to see something happen, but they are extremely united, and I don't think I have ever seen unity like this in the Republican Party," he declared. "It's really a beautiful thing to see."

That said, the costs and complications of the partial government shutdown continue to increase: Security lines are getting longer at some airports, trash is piling up at national parks and 800,000 federal workers are about to miss a paycheck Friday. A Politico/Morning Consult poll released this week showed Trump bearing the brunt of the blame: About half of Americans hold the president responsible; a third blame congressional Democrats.

Among Republicans surveyed, the blame goes to Democrats by almost 5-1. Trump's rating within his party actually ticked up a few percentage points from before the shutdown, and 84 percent express approval of the job he's doing as president.

Since his inauguration, Trump has made more efforts to hold the support of those who voted for him than he has to expand his appeal to those who didn't. That helps explains his unyielding stance in a standoff that would have prompted most of his predecessors to seek a settlement and move on.

"By all objective standards, it's all downside for him – except for one," Mo Elleithee, a veteran Democratic strategist and executive director of Georgetown University's Institute of Politics and Public Service, said in an interview. "That's his base. His base is loving it. They're eating it up, and it's increasingly clear that's all he cares about. Anything else is irrelevant."

Thursday on Capitol Hill, House Speaker Nancy Pelosi tweaked congressional Republicans for that unity, for refusing to break with Trump on this or much of anything else. "Did you take an oath to the Constitution or to Donald Trump?" she asked. She warned Trump that he could put his partisan solidarity at risk if he delivers on his threat to declare a state of emergency as a way of bypassing Congress for wall funds.

"I think the president will have problems on his own side of the aisle for exploiting the situation in a way that enhances his power," she said, a reference to concerns expressed by Florida Sen. Marco Rubio and other Republicans that future Democratic presidents would feel empowered by the use of emergency declarations to pursue policy goals. "I think he's going to have to answer to his own party on usurping that much power."

Trump gave no sign of being deterred.

"I have the absolute right to declare a national emergency," he said, an assertion some legal analysts disputed. “If this doesn’t work out, probably I will do it – I would almost say definitely.”

On Day 20, the end of the shutdown didn't seem to be getting closer. It seemed to be getting further away. Pelosi didn't signal any willingness to relent in the Democrats' refusal to approve funding for a wall. In a tweet, Trump blamed "Democrats intransigence" as he announced he canceled a trip to the World Economic Forum in Davos, Switzerland, because of the shutdown, a sign he thinks it may not be settled by then.

His departure was slated for Jan. 21 – when the shutdown would hit Day 31.