In late October, President Trump spoke with one of his top advisers after reading reports of election forecasting models that predict a win for him based on the economy’s performance.

These projections — from Moody’s Analytics, Oxford, and Yale economist Ray Fair -- gauge things like the unemployment rate and income growth to predict the election’s outcome. Three of the leading models show Trump winning easily in 2020.

“He was delighted by those stories. He’s been very interested in them,” said Larry Kudlow, director of the White House National Economic Council, arguing they reflect a “middle class worker boom" under Trump.

Engulfed in an impeachment inquiry and facing eroding support, Trump has turned to the strength of the U.S. economy as a sign that he is likely to be reelected. Since World War II, no U.S. president has lost reelection when the unemployment rate was below 7.4 percent. No president has even run for reelection when the jobless rate was as low as it is now – 3.6 percent.

Trump will soon test this precedent. His poll numbers remain very weak, and his support in suburbs has eroded steadily. A number of political experts say traditional measures of economic success may not prove decisive enough for voters to give Trump a second term.

On Tuesday, one day before the House of Representatives begins public impeachment hearings, Trump plans to give a speech in New York on trade and economic policy, potentially setting up a contrast with Democrats over priorities heading into next year. A White House spokesman disputed that Trump has poor approval ratings, pointing to polling from the 2016 election that he said incorrectly demonstrated the president’s unpopularity.

“President Trump has created the hottest economy in modern history, and you can be certain that it will be a persistent theme emanating from the Trump campaign,” said Kayleigh McEnany, Trump’s national press secretary, in a statement.

But it is far from clear whether Trump can bank on the economy for his reelection. Political scientists note electoral models based on the economy may miss crucial factors, like rising health care costs, as well as how voters view the personal behavior of the president.

State elections earlier this week may have also underscored the president’s political danger, as Republicans suffered embarrassing losses even in Kentucky and Virginia, where economic growth remains relatively strong. And signs of voter discontent with the president have emerged in crucial swing states, including over health care.

"Typically, these sorts of models include only economic variables, plus some measure of incumbency. The problem is that those aren’t the only things that matter,” said Alan Abramowitz, a political scientist at Emory University. “They leave out so much, including what voters think of a president’s honesty and trustworthiness, as well as whether they agree on his policies on issues like health care, the environment and a whole range of things.”

About 44 percent of voters say the economy has improved during the Trump administration, according to a recent Washington Post-ABC News poll. But in “Blue Wall” states Michigan, Minnesota, Pennsylvania, and Wisconsin, voters give Trump a -21 percentage point net rating on health care, according to a poll released this week by the Kaiser Family Foundation and Cook Political Report. This tension has made it hard for some forecasters to predict how Trump might fare.

Democratic lawmakers and a number of experts also dispute that the economy gives Trump a decisive political advantage. They point out that bankruptcies in farm country are rising and wage growth has remained sluggish. More Americans are homeless or without health insurance over the last two years, among other trends that hurt the working class, such as persistent poverty, high income inequality, and a devastating opioid epidemic.

“Given the structural inequities embedded in our society, Democrats’ agenda is as relevant at 3 percent unemployment as it is at 7 percent,” said Jared Bernstein, a former economic adviser to Joe Biden. “It doesn’t obviate the progressive agenda at all. There are lots of people and lots of places that have been left behind.”

The White House has still received some unambiguously good economic news compared to the summer, when there were growing fears that the economy could be sliding into a recession. Manufacturing output was weakening. Trade tensions with China were at a high. The stock market gyrated wildly. Sen. Elizabeth Warren (D-Mass.), echoing many economists, warned of a “coming economic crash.”

But since August, several key variables have gone the administration’s way. The Federal Reserve has cut interest rates, generating additional spending in the economy. Two measures of U.S. business activity, after tanking over the summer, leveled off in the fall. Trade tensions appear to have subsided.

Recent Commerce Department data show the economy is slowing, but it is still growing, appearing to steer clear of a recession for now. Gas prices and inflation are low. The stock market has hit new heights.

At the same time, Trump’s Democratic opponents have increasingly called for far-reaching government interventions in the economy. Kevin Hassett, who recently stepped down as chair of the White House Council of Economic Advisers, said Trump will lay out a “second-term agenda” that presses the contrast with Democrats’ economic agenda. White House advisers and congressional Republicans have begun discussing the contours of a second tax cut package.

Trump may turn to pointing to the number of people who have gotten insurance by becoming employed, Hassett said.

“It’s ironic: Typically, it’s at the peak of a financial crisis, when markets are collapsing, that you see demands for radical change,” Hassett said. “He’s going to focus on the state of the economy and a different version of what to do for the next four years.”

White House advisers and Republican allies in Congress believe that Trump can help himself by celebrating the economy’s resurgence. But getting the president to do so may prove difficult. Sen. Rick Scott (R-Fla.) said he has urged Trump to talk more about how “the economy is on fire” and not get distracted by other issues, but suggested the president does not always listen to these pleas.

“He always takes it in," Scott said of his push to get Trump to focus on the economy, “and then goes and does whatever he wants.”

Some research suggests Trump may be wise to not solely rely on the state of the economy. Sean Freeder, of the University of California, Berkeley, has found that the impact of the president’s economic performance on his reelection bid has diminished over the last several decades as voters increasingly interpret it through a partisan lens where they are likely to approve of a president of their own party.

Voters also tend to base their vote on how the economy performed in the year leading up to the election, rather than evaluating a president’s economic performance over his four-year term, said Matt Grossmann, a political scientist at Michigan State University. That suggests a downturn could still hurt Trump. Grossmann cited the example of Ronald Reagan, who presided over a weak economy in 1982, when the unemployment rate was 10.8 percent. But in November 1984, when Reagan faced voters again, the unemployment rate had fallen to 7.2 percent.

“The economic performance of a president still matters, but in a polarized and partisan environment it’s mattering a lot less,” Grossmann said. “Many voters used to have little to go on to evaluate the president other than how things were looking on the economy. Now, they rely on much more.”