In this polarised political environment, party leaders are more likely to adhere to the wishes of their base than the average American. So when their most loyal voters are telling them not to cave, what incentive is there to compromise?
The starkest example of this is Trump himself, who was willing to pass a clean funding bill, at least temporarily, to avoid a government shutdown and buy more time for wall funding talks.
But when his base scoffed and threatened to turn on him, he quickly retreated and has held a firm line ever since. And with no one in the Republican Party in Congress calling him out or willing to cross him, the GOP position is US$5.7 billion for the wall or no functioning government.
A recent Washington Post/ABC News survey asked the question a little differently, giving people the choice between holding firm or compromising to open the government. Those who opposed the wall were roughly split on it, with 49 per cent saying Democrats should dig in while 44 per cent said they should compromise.
Those who support the wall, however, were more likely to expect Trump to hold out - 56 per cent said Trump should demand the money even if it extends the shutdown, while 38 per cent said he should compromise.
What political incentive does either side have if all they are hearing from their base is that they shouldn't cave?
If House Speaker Nancy Pelosi gives Trump his funding absent some big deal on the dreamers - undocumented immigrants brought here as children that the Obama Administration protected from deportation - her base will be furious, especially since Trump is on record saying he'd own the shutdown.
If Trump agrees to open the government for less than his US$5.7 billion figure, his supporters have already shown how angry they'll be.
There's been no public polling yet on Trump's announcement over the weekend that he would extend protections for dreamers and immigrants with temporary status for three years in exchange for his wall money.
Democrats immediately said it's a nonstarter because it includes a number of poison pills like limiting the number of eligible dreamers and making minors apply for asylum in Central America instead of when they arrive in the US.
On Capitol Hill this week, the Senate GOP will take up Trump's proposal to make it appear that they are offering concessions. And in the House, the Democrats will vote to open the government with US$1.3 billion in extra border security money that couldn't be used for construction of a wall but instead for other security projects.
And in the meantime, the shutdown will go on.