The poll, conducted after last week's New Hampshire primary, comes at a time when the primary field remains extremely fluid with multiple candidates who claim to be best positioned to defeat the president in November.

In Pennsylvania, a key swing state that Trump carried by just over 1 point in 2016, the president trails three of his potential Democratic opponents by at least 6 points. It found former Vice President Joe Biden leading Trump by 8 points, while Minnesota Sen. Amy Klobuchar holds a 7-point lead and former New York Mayor Mike Bloomberg leads Trump by 6 points.

It found closer races between Trump and Vermont Sen. Bernie Sanders, former South Bend Mayor Pete Buttigieg and Massachusetts Sen. Elizabeth Warren. Sanders and Buttigieg hold 4-point leads over Trump, while Warren’s 3-point lead falls within the survey’s margin of error.

In Michigan, where only .3 percentage points separated Trump and Hillary Clinton in the 2016 contest, the survey shows the traditionally blue state remains in play in 2020 but foreshadows another nail biter. Sanders and Bloomberg, who both top Trump by 5 points, and Biden, who leads Trump by 4 points, are the only candidates whose lead falls outside of the margin of error in Michigan.

Buttigieg and Klobuchar, candidates who have campaigned hard on their appeal to moderate and Midwestern voters, each lead the president by just 1 point in Michigan, the poll found.

Thursday's survey offers a contrast with recent national polling that has typically shown the top Democrats with more of an advantage in head-to-head match ups in a hpothetical general election against the president. The most recent Quinnipiac poll of nationwide registered voters, for example, found the top Democrats beating Trump by anywhere from 4 to 9 points.

"Three different states, three different scenarios, one constant — the economy. It's a top issue for voters, and it's giving President Trump a strong tailwind," Quinnipiac University polling analyst Mary Snow said in a press release. "Wisconsin voters give him a job approval rating above 50 percent, higher than what he receives nationally and in Pennsylvania and Michigan. These Wisconsin numbers are a red warning sign for Democrats that rebuilding the 'blue wall' in 2020 may not be so easy. But it's a long way to November."

The Quinnipiac University poll was conducted from Feb. 12-18 via landline and cell phones among a sample size of 845 self-identified registered voters in Michigan, 849 self-identified registered voters in Pennsylvania and 823 self-identified registered voters in Wisconsin. Results from each state have a margin of error of 3.4 percentage points.

The Quinnipiac survey did not include businessman Tom Steyer — who has trailed most of the Democratic field in national polls but is hoping to pull off strong performances in the next two nominating contests — in its head-to-head match ups.