President Donald J. Trump walks out to announce a deal with congressional leaders to temporarily reopen the government while talks continue on his demand for border wall money, on the 35th day of the partial government shutdown, the longest in US history, in the Rose Garden at the White House on Friday, Jan. 25, 2019 in Washington, DC.

President Donald Trump begins his 2020 re-election campaign with a fighting chance but fighting from behind, a new NBC News/Wall Street Journal poll shows.

The survey shows that Americans, by 48 percent to 41 percent, plan to vote for the Democratic candidate opposing the Republican incumbent. That represents a narrowing of the double-digit deficits the NBC/WSJ poll found in December 2017 and 2018.

His standing is worse than that of his immediate predecessors George W. Bush and Barack Obama, both of whom led generically described opponents at similar points. Bill Clinton trailed by a slightly smaller margin in January 1995, though like Bush and Obama he went on to win a second term.

One positive sign for the president: overall approval of his job performance has ticked up to 46 percent of Americans since the end of the government shutdown; 52 percent disapprove. In January, 43 percent approved and 54 percent disapproved of his performance.

Yet the survey underscores a series of political obstacles. Trump faces double-digit deficits among voters under 50, women and independents.

College-educated white women favor a Democrat by 26 percentage points, while Hispanic voters back the opposition party nominee by 40 points. Six in 10 Americans oppose his declaration of national emergency on the southern border with Mexico and believe he has not been honest about Russian interference in the 2016 presidential race.

And though Trump enjoys overwhelming 86 percent job approval among fellow Republicans, they are far from universally opposed to another GOP candidate in 2020. Among voters who say they plan to vote in Republican primaries, 37 percent would like to see a GOP challenger to Trump while 59 percent would not.

The poll flashed a caution light for 77-year-old Vermont Sen. Bernie Sanders, the self-styled Democratic socialist who recently kicked off another White House bid. Among a series of candidate attributes, "someone over age 75" and "a socialist" ranked as the least desirable.

Results were more encouraging for other members of the diverse field of Democratic 2020 candidates. Two-thirds or more of Americans described themselves as either enthusiastic or comfortable with a presidential candidate who is gay, female or African-American.

Overwhelming numbers said the same about a white man. Smaller majorities expressed comfort or enthusiasm about the prospect of an independent, under 40, business executive or evangelical Christian candidate.

On issues, the poll found more problems for Republicans than Democrats. Fifty percent or more of Americans called the GOP stance "outside the mainstream" on climate change, abortion, health care and immigration.

The worst Democrats fared on any policy area was "fiscal issues, such as taxing and spending," where 47 percent called them "outside the mainstream. An identical 47 percent called Republicans outside the mainstream on fiscal issues.

The telephone survey of 900 adults, conducted Feb. 24-27, carries a margin for error 3.27 percentage points.