President Biden came into office with an ambitious agenda and an avowed willingness to try to make it happen. The progressive left preferred other candidates in the Democratic presidential primary last year, but Biden’s perceived electability — downstream from his political centrism — helped earn him the nomination. As president, though, he’s been very willing to try to enact big changes focused on areas at the forefront of the left’s agenda: more support for parents, addressing climate change, expanding health-care access.

Enacting those changes, though, depends on political support. Biden and his allies have expressed understandable frustration at how coverage of Democratic efforts to pass a spending bill have centered on its price tag, but the components of the legislation, intended to accompany the bipartisan infrastructure bill, fluctuate depending on the cost. That’s mostly because the party can’t lose a single vote in the Senate, meaning it can’t lose the vote of either Sen. Joe Manchin (W.Va.) or Sen. Kyrsten Sinema (Ariz.), two of the most moderate Democratic legislators.

But it also can’t lose votes in the House, where the margin is only barely more robust. Lose a few representatives — say, ones worried about their reelection chances next November — and suddenly things quickly go south. This is largely why it’s useful to track polling on the 2022 midterms, not just out of curiosity (which is fair enough) but because perceptions of what will happen in the elections will shape what legislators do before then. If Biden becomes deeply unpopular or Democratic support plunges in the generic congressional ballot, a measure of how Americans are likely to vote in House races, you might expect to see more pressure against the Biden/Democratic agenda.

In the abstract, things look okay for the party at the moment. FiveThirtyEight’s trend in generic-ballot polling shows the Democrats with a slight lead. They need an advantage in the generic ballot in order to pull even, both because Democratic turnout has been smaller in recent off-year elections and because there’s been a recent advantage for Republicans in the House, allowing them to win more seats with fewer votes.

Comparing the current average with where the polling was in 2017, before the Democrats had a massive win in House races, you see that the party’s position is not nearly as robust as it was. On Oct. 15, 2017, Democrats had a seven-point advantage on the generic ballot. Now, the edge is only three points.

There’s another important factor to consider: Biden’s approval rating. House races are increasingly correlated to presidential voting, a measure of the nationalization of local races. A Democrat running for reelection in a close race very much wants a popular Democratic president, as surely as she was happy to have an unpopular Republican president four years ago. Presidential approval ratings have long correlated to the results of midterm elections, as data from Gallup shows. If Biden is at 50 percent approval when the midterms roll around, history suggests that the Democrats will lose several dozen seats, giving Republicans control of the House.

Gallup’s current approval rating for Biden would have his party losing nearly 50 seats, if it hewed closely to the trend line (which it won’t). As that chart shows, only twice have presidents seen their parties gain seats in midterms. In each case, the president was above 60 percent approval.

Biden is not likely to hit 60 percent approval. Over the past decade or so, presidential approval has been largely static, with partisans holding strong opinions and most of the movement occurring with independents. That’s largely been true for Biden, too. His drop in approval, as measured by YouGov in polling conducted for the Economist, has largely been a function of big declines among independents since late May. Overall, his approval rating has fallen 14 points among independents, including 12 points on the economy. At one point he seemed to be buoyed by his handling of the coronavirus pandemic, but since the emergence of the fourth wave of cases in late June, that’s slipped, too.

Biden and his party need to hold independents to be successful electorally, and perceptions that independents are rejecting his policy initiatives are likely to carry more weight for his allies than promises that Americans will be wooed by their implementation. Again, that latter argument may be right — that people will see changes in their quality of life that they will attribute to Biden and Democrats. But that’s a tougher sell for a wobbling Democrat than polling showing that independents are souring on Biden’s approach.

On Thursday, Gallup released new polling asking an interesting question: Is government doing too much? In 2020, with the pandemic emerging and the Trump administration’s response lacking in many ways, Americans were more likely to say they wanted the government to do more, by a 13-point margin. This year, a majority say the government’s trying to do too much. That position has a nine-point advantage, a flip of 22 points. Among Democrats, the flip was 10 points, and among Republicans, 13.

Among independents, the shift was 37 points.

Even within Biden’s party, polling from CNN indicates that the further-left part of the caucus isn’t overwhelmingly winning the big-picture debate. Democrats and independents who lean to the party broadly support the specific components of the Democratic bill. But asked whether it’s progressives or moderates who are helping the party more, Democrats were about split. Among independents who lean left, the moderates held a double-digit advantage.

None of this means that passing Biden’s full spending bill would hurt the party or that it wouldn’t help. This also does not mean that the party should fret over generic-ballot polling 13 months before the elections; in fact, it shouldn’t. But those advocating for Biden to leverage his mandate to go big on spending need to recognize that the mandate has eroded, and that the large group of independents is skeptical of Biden and the broad strokes of his policy agenda, even if they endorse the specifics.

Politics is not rational. If you felt that your job hinged on what you do right now, though, and you see one choice as particularly risky to that end, would that influence your decision-making?