Despite the tax plan actually undercutting key Trump campaign issues like reducing the deficit and helping the middle class, it’s approved by supporters of the president. (Brendan Smialowski/AFP/Getty Images)

There’s been a theme to polling about the Republican tax-reform measure. It’s broadly unpopular and generally seen as titled toward large corporations at the expense of working-class Americans. On Thursday, CBS News released a new poll matching those perceptions, as polls from Gallup and Quinnipiac University did earlier this week.

After those surveys came out, we noted that the tax plan was less popular than President Trump — which, in one sense, is something of an achievement. In CBS’s polling, that’s less the case. In fact, polling for the tax plan mirrors Trump’s approval closely.

There’s a lot of overlap between views of Trump and of the tax plan in general.

In early November, The Washington Post and our partners at George Mason’s Schar School found the same thing, with 37 percent of the country approving of Trump and 33 percent of Americans approving of the tax plan. Among those who approved of Trump, 75 percent also approved of the tax plan. Among those who disapproved of Trump, 78 percent also disapproved of the tax plan.

On the surface, this makes sense. You like what the president is doing and the president is pushing this tax bill, therefore, you like the tax bill. But stepping back a few feet, it gets murkier. Trump is the sum of a lot of things besides this tax plan, and the tax plan has a lot of components that are unrelated to Trump. Despite the tax plan actually undercutting key Trump campaign issues like reducing the deficit and helping the middle class, it’s supported by Trump supporters.

We talk a lot about the partisan divides in the United States, with good reason. Pollsters, including Pew Research, have tracked rising partisanship in a number of ways. When it comes to a number of issues, there’s no wider gulf demonstrated between people in different demographic groups than between people in different parties.

This holds for political issues, obviously, but also for things, like the types of neighborhoods in which people prefer to live.

Partisans hold increasingly different positions on issues, are unlikely to have many friends from the opposing party, and are likely to see the policy priorities of the opposing party as a threat to the country.

We can think of it more broadly as tribalism — a formulation that makes particular sense in this moment because much of the concentration of political belief centers on Trump more than his party. There’s a lot of overlap between Republicans and Trump supporters, certainly, but that’s not the full picture. In our November poll, 48 percent of those who approve of Trump identified as Republicans; 33 percent identified as independents.

The tribe of Trump — Trumpists, as some have dubbed the group — make up somewhere between a third and 40 percent of the country. This itself overlaps with (but probably extends past) his much-discussed base of support, that group which rallied to his side early in the Republican primary process, building a kernel of support that allowed him to outlast 16 other contenders for the nomination. We see this consistent pattern in polling where somewhere between 30 and 40 percent of Americans agree with Trump’s avowed position on an issue and more than half of the country holds the position that opposes Trump’s. That’s the tribe.

Last month, Politico reported that Trump still pays a lot of attention to polls, a habit for which he became infamous during the primary. It’s just that the polls he looks at now are focused slightly differently.

“Aides in the White House often show Trump polls designed to make him feel good, according to aides and advisers,” Josh Dawsey and Steven Shepard wrote. “Usually they’re the ones that focus just on voters who cast ballots for him in 2016 or are potential Trump supporters — Trump’s base — but occasionally include public polls like Rasmussen, depending on what the numbers say.”

Neil Newhouse, a pollster who worked on Mitt Romney’s campaign in 2012, explained how such a focus could be rationalized.

“Because 35 to 40 percent of Americans are never going to support anything he does, why should I spend my money trying to find out what they think?” he said.

The implication, then, is that Trump is primarily interested in how those in his tribe view the decisions he’s making. This isn’t really surprising, given that Trump’s hard-right positions never wavered from the moment he entered the 2016 campaign and given how little he’s done to try to convince those who dislike him to give him a chance. (A recent poll from PRRI showed that most who disapprove of Trump say they won’t change their minds — but 20 percent of Americans disapprove but could potentially be convinced to support him.)

When we looked at the unpopularity of the tax bill last month, we noted the differences between Americans in general and members of Trump’s party.

When it came to Americans in general, the story looked like this: “Republicans (22 percent approval as a party) move a tax bill (25 percent approval) to be signed into law by Trump (37 percent approval).”

When it came to the views of only Republicans, a decent-but-imperfect proxy for Trump’s tribe, this was the story the polls told: “Republicans (66 percent approval as a party) move a tax bill (60 percent approval) to be signed into law by Trump (81 percent approval).” In CBS’s new poll, those figures are slightly different; Trump’s approval is 77 percent and the tax bill is at 76 percent, but the point remains.

Maybe the only group that really likes what you’re doing is your tribe. But if you only evaluate your success against what that tribe thinks, you’ll end up thinking you’re doing pretty well.