President Donald Trump is doing well with his base — rural and evangelical voters and white men without college degrees.

However, the inaugural Grinnell College National Poll conducted over the Labor Day weekend found that after 19 months in office, Trump would face a challenging road to re-election in 2020.

The poll of 1,002 people, including 779 likely voters, found that if the 2020 vote were held today, just 36 percent of likely 2018 voters definitely would vote to re-elect Trump, 17 percent would consider someone else and a 43 percent definitely would vote for someone else.

The poll of landline and cellphone users was conducted by Selzer & Co. and has a margin of error of 3.1 percentage points.

The finding present a “challenging landscape” for Trump, said Peter Hanson, associate professor of political science and specialist in American politics at the private Grinnell College.

“He has not succeeded in broadening his base,” Hanson said. “Two years is a long time in politics, and a lot will depend on his Democratic opponent, but a substantial majority of likely voters are either seeking new leadership or ready to consider it in 2020.”

Poll director J. Ann Selzer called Trump’s support among women “on the gloomy side.” Only 29 percent of women overall say they would definitely vote to re-elect Trump.

While his margin with only white women is higher — 36 percent, it drops to 26 percent among suburban women.

The good news for Trump is that he’s doing better among likely voters than other respondents by 4 percentage points — 43 percent to 39. But 50 percent of both groups disapprove of his job performance.

The president might take comfort in having a favorability rating higher than Congress.

Among likely voters, the poll found, 45 percent view him favorably while 51 percent view him unfavorably. For Congress, the poll sample gave the House a favorable/unfavorable rating of 31 to 52 percent and the Senate a favorable/unfavorable rating of 30 to 55 percent

But the U.S. Supreme Court topped them all, with a 59 percent favorable to 24 percent unfavorable rating.

More than two-fifths — 42 percent — of those polled said their view of Trump now is more favorable than when he was elected. That included 26 percent who said their view was a lot more favorable.

A majority of 53 percent said their views are more unfavorable, including 44 percent who say they are a lot more unfavorable.

Likely voters are hopeful about the future of the nation. Sixty percent said they are more hopeful about the way things will be following this year’s midterm elections while 30 percent said they are more fearful. Responses were similar about the 2020 election, with 59 percent expressing hope and 29 percent fear. The optimism was broad-based, including both Trump and Hillary Clinton voters, with men more optimistic than women.