Voters who are betting a strong economy will reelect President Trump might be in for a rude awakening. Research shows that the bond has weakened between strong economic performance and incumbents winning. It has been partially replaced by party affiliation.

"Citizens view the world through a partisan lens," said Ellen Key, associate professor of political science at Appalachian State University. She added via email that "there's a certain segment of the population that doesn't like the president regardless of how the economy is doing."

Key co-authored the aforementioned research, titled "Motivated reasoning, public opinion, and presidential approval," and said that party affiliation can both hurt and help a candidate running for the high office.

"The president's co-partisans ... are predisposed to give the president more credit for economic performance because they share a party affiliation," she stated.

Key's research is supported by recent polling that shows people are feeling more confident about the economy even as Trump's job approval rating remains negative on net.

Gallup recently found that a solid majority (59%) feel better off than they did last year, and nearly three-quarters (74%) of respondents expect to do better next year. The National Federation of Independent Business's small business Optimism Index is nearing its record high — partly because of what Trump has done during his first term in office. These positions are reflected in the public's perception of how Trump has handled the economy. (According to polling, 56.3% approve, while 39% disapprove.) Still, overall, more people disapprove (52%) of the job that he is doing than those who approve (45.1%), according to RealClearPolitics.

One reason for the disconnect is that respondents are taking a partisan view of his presidency and concluding that they don't like him, Key's study found. It also discovered that political opponents would highlight the economy when they blame each other for it faltering. Democrats blamed Trump for the damage caused by his tariffs but did not cheer his phase-one trade deal with China or the enactment of the U.S.-Mexico-Canada Agreement. In the House, 193 Democrats supported the measure. In the Senate, 37 Democrats voted for it, and yet the applause from the Left was muted at best.

It hasn't always been this way, research shows. President Bill Clinton's job approval rating surged to over 70% after the House impeached him because of the expanding economy. Clinton left office in January 2001 with an unemployment rate of 4.1% and a still-expanding economy. Economic conditions are similar, if not better, under Trump. The unemployment rate in January was 3.6%, and the economy grew at an annual rate of 2.1% in the fourth quarter of 2019. And yet, these figures showing a strong economy have not lifted the president's overall approval rating into positive territory.

Wall Street has taken notice of economic indicators playing second fiddle to political considerations. Morgan Stanley strategists last month issued a warning to readers stating that "past presidential incumbents have typically won a second term if the economy has been strong. Trump might not be so lucky."

The strategists deemed the notion that a strong economy will lead to Trump's reelection a "common misconception among investors." They also note that no president with a net negative approval rating has won reelection since World War II. Trump's job approval rating has been negative since he took office in January 2017.

One development that should give Trump supporters hope is that his job approval rating has increased — not because Democrats are coming around to him but because more Republicans and independents are starting to support him, according to Gallup.

"His 94% approval rating among Republicans is up 6 percentage points from early January. … The 42% approval rating among independents is up 5 points," stated the polling organization in a Feb. 4 release. Gallup cites that the poll was conducted during the Senate's impeachment trial of Trump and that over half (52%) of respondents supported acquittal. Impeachment of a president is a political process, not a legal one.

Currently, the top Democrats running for the Oval Office, including Sen. Amy Klobuchar of Minnesota, beat Trump in head-to-head matches for the White House, according to RealClearPolitics. Trump would need more support to win reelection, but the resilient economy may not be enough.