Trump defenders correctly point out that maintaining high job growth is tougher when unemployment is already low, as it’s been since about 2015. But other measures show the same pattern of continuity between administrations. Pending final revisions, the Bureau of Economic Analysis concluded the economy grew 2.3 percent in 2017. That generally tracks with Obama’s recent record: It’s less than its annual growth in 2014 and 2015, and slightly more than its improvement in 2013 and 2016. Average hourly wages also grew 2.3 percent last year—considerably more than in 2013 and 2014, but only slightly more than 2015 and less than 2016. And while the roughly 20 percent gain in the S&P 500 last year did significantly outpace Obama’s recent record, Trump still lagged his predecessor’s showing in 2013 (as well as his showing in his own first year, 2009).

Another obstacle for the GOP is that, unless and until wage growth accelerates for a sustained period, not everyone may view economic conditions the way Trump did when he called the country’s current state a “new American moment.”

Democratic pollster Stanley Greenberg consistently argued throughout Hillary Clinton’s 2016 race that the Democrats’ determination to promote the economy’s improvements under Obama would clang against the ears of working- and middle-class voters still struggling to meet their bills. Now, Greenberg thinks Republicans are on the verge of making the same mistake, particularly with blue-collar white women who remain economically strained. “I want that battle,” he told me. “I think that will backfire.”

Equally important, the two other major election dynamics apparent during the speech could influence voters as much, or more, than the economy does.

One was evident in Trump’s extended discussion of immigration. He described his proposal to provide a pathway to citizenship for young people brought to the country illegally by their parents as part of “a down-the-middle compromise.” But, in fact, by linking protection for the “Dreamers” not only to funding for his border wall, but also to the largest reductions in legal immigration since the 1920s, Trump offered a solution unacceptable to many voters—including all immigrant advocacy groups, almost all Democrats, and even many centrist Republicans.

With that proposal, Trump embodied the second key dynamic shaping 2018: his pattern of proposing policies aimed squarely at his base, with few concessions to any constituencies beyond it. That tendency largely explains why Trump and congressional Republicans could not attract a single House or Senate Democrat to their legislation to replace the Affordable Care Act or to their tax bill. Even the infrastructure plan Trump pushed on Tuesday emphasizes private profit so heavily that few Democrats may embrace it, despite their longtime advocacy for building new roads and bridges.