Senate Republicans have seen the same polling as everyone else.

More than 50 percent of Americans blame President Trump and the GOP for the nearly four-week-long shutdown of some federal agencies, while just 29 percent blame Democrats, according to a Washington Post-ABC News poll. By a 63-to-32- percent margin, voters oppose shutting down parts of the government as a bargaining chip to force Congress to provide more than $5 billion for a border wall, a Quinnipiac Poll found.

But Republicans are in no hurry to get themselves out of this jam. Just look at their political geography.

At home in Wyoming over the weekend, Sen. John Barrasso (R) attended several local GOP events and heard the same message everywhere. “Build the wall, build the wall, build the wall,” Barrasso recalled.

He said Wyoming voters, who gave Trump almost 68 percent of the vote in 2016, do not want to reopen the government until the president is happy with the level of border security.

“They also would like to see the government open, but not at the expense of not accomplishing what the president has promoted,” Barrasso said.

His Wyoming colleague, Sen. Mike Enzi (R), up for reelection next year, is only worried about one election, his GOP primary in the summer of 2020.

Out of 22 Republican seats up in 2020, 18 are from states that Trump won by comfortable margins.

Just two, Sens. Cory Gardner (R-Colo.) and Susan Collins (R-Maine), are running in states that Democrat Hillary Clinton won in 2016. In fact, those two are the only Republicans, out of all 53, representing states that Clinton won.

Two other Republicans, Sens. Thom Tillis (N.C.) and Martha McSally (Ariz.), are running next year in states where Trump won by less than five percentage points.

This is a better map for Democrats than 2018 — when they defended 10 seats in Trump states and suffered a net loss of two — but it is not a great map.

That makes it unsurprising to see Collins, Gardner and Tillis as part of a group trying to jump-start bipartisan talks to find a resolution to the impasse, talks that so far have produced nothing tangible.

But very few other Republicans feel any dis­cern­ible political pressure to buckle to Democratic demands, despite national polling that shows Trump getting crushed during this shutdown, now the longest in history.

“This shutdown really depends on where you sit and what part of the country you’re in,” Sen. Lisa Murkowski (R-Alaska) said Tuesday. Her state is heavily dependent on federal workers in the Interior Department and similar agencies overseeing fishing and energy industries, almost all of which are shuttered at this point.

Murkowski’s aides have been fielding plenty of calls from angry constituents demanding the government function again.

Are other GOP senators facing a similar influx of calls?

“Not really,” Sen. Mike Rounds (R-S.D.) said.

“Not many, not many,” Sen. John Cornyn (R-Tex.) said.

Both Rounds and Cornyn face reelection in 2020 but are not as focused on the general election.

Rounds said that in a battle of Trump vs. Democratic leaders, the president “definitely” takes his state, where he won by more than 30 percentage points in 2016.

“The president’s going to win that battle,” Rounds said.

Indeed, among conservative voters, support has grown sharply for Trump’s position, making it potentially perilous for GOP incumbents to break with the president.

Support among Republican voters for building the border wall jumped from 71 percent to 87 percent over the last year, according to the Post-ABC poll, findings that were almost identical to the Quinnipiac poll.

Moreover, the number of GOP voters who “strongly” support the wall grew 12 percentage points over last year, up to 70 percent.

“I think Republican primary voters are with the president,” Cornyn said.

Even Sen. Joni Ernst (R-Iowa), who is often listed as a potential Democratic target in 2020, has shown little sign of breaking with Trump.

She won a GOP leadership post, joined the Judiciary Committee in the aftermath of a tense partisan showdown over the confirmation of Supreme Court Justice Brett M. Kavanaugh and has not wavered in support of the wall.

“They are inadmissible, they are illegal immigrants. And it’s not just about our southern border. It is about every community, every town here in the United States,” Ernst said at Tuesday’s GOP conference, at the side of Senate Majority Leader Mitch McConnell (R-Ky.).

Despite Iowa’s swing-state tradition, Trump defeated Clinton by nearly 10 percentage points in 2016. Democrats were more competitive last year, claiming three of the state’s four seats in the House and splitting even on six races for statewide office.

But most Senate Republicans look back at the 2018 election and see a two-seat gain after they mostly stuck with Trump.

Gardner and Collins are starting off this election season in potentially bad terrain, but GOP strategists are banking on winning back the seat of Sen. Doug Jones (D-Ala.) after his upset victory in the 2017 special election.

Democrats need to gain either three seats, and win the presidency, or four seats to claim the majority. For now, Senate Republicans are betting that is a tall order that will only come to pass if Trump goes into a tailspin that takes a bunch of them down with him.

That means standing with Trump on his demands for a wall, while bemoaning the shutdown. “I think the shutdown is a dumb thing to do. I didn’t run for office, and people didn’t elect me and others, to preside over shutdowns. They elected us to govern, and this is all about politics right now,” Cornyn said.

He believes it is up to House Speaker Nancy Pelosi (D-Calif.) and Senate Minority Leader Charles E. Schumer (D-N.Y.) to work with Trump to come up with a deal.

Murkowski said she’s not sure what Trump would accept, but his support is a requirement, both legally, his signature on the bill, and politically, to give shelter to her GOP colleagues.

“We’ve got to get the president to support it,” she said. “Without that, we’re still stumbling along.”