We’re pretty far down a tricky path for President Trump, whose promises on the 2016 campaign trail to build a wall on the border with Mexico were never likely to come to fruition given the process for getting legislation passed by Congress. Much of the focus on Trump’s bold assertions focused on his proclamations that Mexico would cover the costs for the wall, but the wall itself, particularly as described by Trump and particularly once it became intermingled with Trump’s views on immigration, faced a rocky path forward.

During the past two months, the bumpiness of the path became manifest: Trump blocked government funding to try to force Democrats to capitulate; they didn’t; he took the loss. But on Friday, Trump launched a last-ditch effort to move the wall forward, declaring a national emergency focused on the border, potentially allowing him to allocate money to get it built. The courts will probably decide if that happens.

The move is not popular. As our Aaron Blake wrote on Tuesday morning, a new NPR-PBS NewsHour-Marist poll shows only about a third of the country thinks the declaration was a good idea. As you might expect, Republicans were more supportive than Democrats.

The shape of that graph should, by now, be familiar. Low overall support that mirrors how independents feel, with partisans at either end of the spectrum. HuffPost’s Ariel Edwards-Levy made a joke about it, following the release of a HuffPost-YouGov poll that showed much the same result.

Every poll has the same pattern: Trump voters love what he proposes, those who voted for Hillary Clinton in 2016 hate it, and others are mixed.

To that point, let’s present the results of that Marist poll as dots instead of columns . ..

. . . and let’s then add in other polling from the past few weeks.

The patterns are clear: Low Democratic support on range of issues and high Republican support. The most positive response is on how Trump is handling the economy, as reflected in a January Post-ABC poll. The least support across parties came when respondents were asked if Trump has made America more respected.

Let’s go further, dumping in a bunch of poll results we aggregated in June.

This covers a broad range of issues, from gun rights to views of Trump’s job performance to comparisons with Democratic leaders on the Hill. But the patterns are consistent: Republicans over 50 percent, Democrats under 25 percent and overall opinions in the 25 to 50 percent range.

This, too, should look familiar. We’ve previously created charts showing the distribution of Trump approval ratings over his time in office. Using data from HuffPost Pollster, here’s how his approval was distributed across various polls by party from January 2017 through December 2018.

Tight clusters, with low approval from Democrats, high approval from Republicans and independents squarely in the 30s.

The last president to see approval clustering like that was the last president, Barack Obama. Obama had a honeymoon period that Trump didn’t, in which Republicans were less hostile to his presidency (until the end of 2009, basically).

But here’s where the problem for Trump emerges. Consider Obama’s approval ratings over the course of his first term with Trump’s.

Similar in broad strokes — but Obama’s overall approval was higher, thanks to his approval from independents being generally higher.

One thing that happened in 2016 that’s underrecognized is that Trump benefited from partisan loyalty. Clinton tried hard to peel away Republicans, but they mostly came home to vote for him. At the same time, independents who liked neither Trump nor Clinton skewed much more to voting for Trump than Clinton, perhaps because he was theoretically more of a blank slate.

Trump’s largely solidified that Republican support, but hasn’t made much headway with independents. On average, Trump’s approval from independents has been 37 percent; through the 2012 election, Obama’s was 43 percent. Correspondingly, Obama’s average overall approval through his first term across all polls was 47 percent; Trump’s has been 42 percent.

Those are big differences that reflect what we see in polls over and over and over. Republicans love Trump and Trump’s worked hard to get them to love him. But his average support from Republicans has been about the same as Obama’s was from Democrats in his first term. Obama lost independents in 2012 according to exit polls, but earned about the same percentage of support from independents that Trump did when he won them in 2016.

If Trump solidifies Republican support, besting how he did in 2016, that will help him. But if he loses more independent support and if Democrats solidify more robustly around their nominee — which seems likely, given the midterm results — that bodes poorly for Trump.

The focus of Blake’s article about that poll about the national emergency is that many groups, including the non-college-educated white men who were the backbone of Trump’s 2016 support, said the national emergency made them less likely to support Trump in 2020. But, more generally, it’s a reflection of the political quagmire in which Trump is mired. He wants to deliver on his probably undeliverable campaign promise, thinking it will keep his base with him. But in the process he has done little to entice other groups to offer him their support.

And so they haven’t.