As the two major political parties prepare to open their national conventions, the race for the White House tilts toward the Democrats, with former vice president Joe Biden holding a double-digit lead nationally over President Trump amid continuing disapproval of the president’s handling of the coronavirus pandemic, according to a Washington Post-ABC News poll.

Democrats kick off their convention on Monday in a mood of cautious optimism, with Biden and his running mate, Sen. Kamala D. Harris (D-Calif.), leading Trump and Vice President Pence by 53 percent to 41 percent among registered voters. The findings are identical among a larger sample of all voting-age adults.

Biden’s current national margin over Trump among voters is slightly smaller than the 15-point margin in a poll taken last month and slightly larger than a survey in May when he led by 10 points. In late March, as the pandemic was taking hold in the United States, Biden and Trump were separated by just two points, with the former vice president holding a statistically insignificant advantage.

Today, Biden and Harris lead by 54 percent to 43 percent among those who say they are absolutely certain to vote and who also report voting in 2016. A month ago, Biden’s lead of 15 points overall had narrowed to seven points among similarly committed 2016 voters. Biden now also leads by low double-digits among those who say they are following the election most closely.

The president’s supporters are more eager than are Biden’s to cast ballots for him, with nearly 9 in 10 calling themselves enthusiastic and 65 percent saying they are “very enthusiastic.” Slightly more than 8 in 10 Biden supporters say they are enthusiastic about voting for him, with 48 percent saying they are “very enthusiastic.”

The motivations of the Trump and Biden supporters remain starkly different, with the president motivating both groups. Almost 3 in 4 who support Trump say they are casting an affirmative vote for the president, rather than to oppose Biden. Among those backing Biden, nearly 6 in 10 say they are voting mainly to oppose Trump rather than mainly to support the presumptive Democratic nominee.

Overall, 54 percent of registered voters say they are following the election “very closely,” a high water mark for polls at a similar point in campaigns over the past 20 years. The share of Republicans and Republican-leaning independent voters who say they are very closely following the campaign stands at 58 percent, the same as it was in early September 2016. Among Democrats and Democratic-leaning independent voters, 53 percent say they are very closely following the campaign, which represents a 13-point jump over this time four years ago.

A majority of Americans — 54 percentsay they approve of Biden’s selection of Harris as his running mate, although views diverge significantly along partisan lines. Among Democrats, 86 percent approve of Harris’s selection, including 64 percent who strongly approve. Among Republicans, 55 percent disapprove with 46 percent strongly disapproving. A bare majority of independents — 52 percent say they approve, while 29 percent disapprove of Biden’s decision.

The poll also finds nearly 8 in 10 Black Americans approve of Harris’s selection as a running mate, including 50 percent who approve strongly. Nearly two-thirds of Hispanic adults approve of Biden’s choice, compared with just under half of White adults.

But 71 percent of adults overall say Harris’s selection will make no difference in how they vote, including majorities of Democrats, Republicans and independents.

Asked about the qualifications of Harris and Pence to assume the presidency, if that were required, the findings are identical, with 54 percent saying they thought each was qualified to take over the highest office in the land should that be necessary. Not surprisingly, majorities of Democrats and of Republicans offer negative views about the qualifications of the other party’s running mate.

Biden and Trump will use the next two weeks to present themselves to the American people through quadrennial conventions that will be held under unique circumstances, absent the traditional packed arenas, balloon drops and other festivities. But the conventions will still afford both Biden and Trump the opportunity to make a mostly unfiltered appeal to voters in hopes of energizing supporters and making their strongest case to persuadable voters.

The findings in the latest Post-ABC poll are in line with a Washington Post analysis of national polls taken in July and August, although some recent polls have shown a closer margin. National polls, however, are only one measure of the state of the presidential race and reflect only the popular vote. To win the presidency, a nominee needs to win 270 electoral votes in the state-by-state competition. While Trump won the electoral vote in 2016, Clinton won the popular vote by millions of ballots.

Trump has indicated his confidence in a second electoral college victory, but at this point, Biden holds an advantage in many of the key battleground states that are likely to determine the outcome in November. That advantage, however, is generally smaller than his national lead in multiple polls. In the Post-ABC poll, Biden has an edge of seven points in states that were decided by five points or fewer in 2016, a margin well within the range of sampling error.

Historically, a president’s job approval rating correlates closely with support in a reelection campaign. Currently, 43 percent say they approve of the job Trump is doing as president, up slightly from 39 percent last month, with 55 percent saying they disapprove. His approval rating today is about midway between his high and low points over the past year of Post-ABC polling.

Trump’s standing with Americans continues to be tied to perceptions of the pandemic and of the way he has dealt with it over a period of months. At present, 59 percent of Americans say they disapprove of his handling of the crisis, while 40 percent approve. That is statistically unchanged from last month. But it is sharply different from March, when 51 percent approved and 45 percent disapproved.

There is widespread disagreement that the coronavirus outbreak is under control — 85 percent of registered voters say it is either just “somewhat under control” or “not at all under control,” while 14 percent say the outbreak is “mostly” or “completely” under control. A clear majority of Americans are worried about their family contracting the coronavirus, a proportion largely unchanged from previous months, and most say the outbreak has had a severe impact on their communities’ economies.

Biden wins clear majority support among voters who are more worried about the coronavirus outbreak, as well as those who say the outbreak has had a severe economic impact on their community or their own finances. Among voters who are very or somewhat worried that a family member will become infected, 65 percent support Biden while 29 percent back Trump.

Nearly half of all registered voters — 49 percent — say the coronavirus outbreak is “not at all” under control. Biden leads 83 percent to 11 percent among registered voters who hold this view. Trump leads with 62 percent support among voters who say the outbreak is “somewhat” under control and receives 90 percent among the smaller share of voters who say the outbreak is mostly or completely under control in the United States.

When asked whether, if Biden were president, the nation’s response to the coronavirus outbreak would be better or worse than it has been under Trump, a plurality of Americans — 46 percent — say better and 24 percent say worse, with nearly all the rest saying it would be about the same.

Biden also scores positively on two other big issues, race relations and health care. By a margin of 26 points (46 percent to 20 percent), Americans say race relations would be better under a Biden presidency. On health care, the margin is net-positive for him by 13 points, 39 percent to 26 percent.

On the question of safety from crime, however, perceptions of what a Biden presidency could mean are not favorable, with 25 percent saying things would be better and 32 percent saying they would be worse. Trump’s campaign has made crime a major focus of its advertising and messages recently, using images of recent protests to assert that Biden and the Democrats are weak on the issue.

On the economy, which was Trump’s strongest asset before the pandemic disrupted it and drove tens of millions into joblessness, Americans are roughly divided three ways when asked whether things would be better or worse if Biden were president. Thirty-two percent say the economy would be better under Biden, 35 percent say worse and 30 percent say about the same.

Along with the pandemic, the state of the economy looms large in the election and Americans currently have a gloomy view. Slightly more than 2 in 3 give the economy negative ratings, including 1 in 3 saying the state of the economy is “poor.” These are the worst findings in nearly six years in Post-ABC polls.

Of the four candidates on the two major party tickets this fall, Trump has the lowest ratings on the issue of favorability, which is a different measure than job approval.

While 42 percent say they have a favorable impression of the president, 56 percent say their impression is unfavorable, including 46 percent who say it is strongly unfavorable. Those numbers have changed little in the three-plus years of his presidency but are better than they were before the Republican convention in 2016, when 31 percent gave him a favorable rating.

Biden has a narrowly positive rating, with 50 percent favorable and 46 percent unfavorable. That is a small improvement since May, when his rating was a net two points negative. But it is better standing than Hillary Clinton enjoyed four years ago, when her favorability was at 48 percent just after her July convention and fell to 41 percent later in August. Majorities rated her unfavorably through the rest of the campaign.

Harris has the highest positive rating of the four candidates on the ballot this year, with 52 percent favorable and 38 percent unfavorable. Pence nearly breaks even, with 44 percent favorable and 46 percent unfavorable.

Biden’s margin of voting support over Trump is built on stronger support among some groups of voters than Clinton achieved four years ago. He is winning independent voters by 17 points, for example, a group Trump narrowly won in 2016, according to network exit polls. Nine in 10 Democrats support Biden and about the same percentage of Republicans back Trump.

Biden and Trump are tied among seniors, a group Trump carried four years ago, although Biden has lost the 10-point advantage he held in May. They are also roughly even among voters ages 40-64. But among voters under age 40, who historically turn out in lower percentages than older voters, Biden leads by 62 percent to 29 percent.

Among voters in the suburbs, a traditional electoral battleground, Biden has a narrow eight-point lead. Trump, who narrowly won suburban voters in 2016, has tried to appeal to them this year by holding himself out as the sole force preventing an influx of minority and poor residents. Still, suburban women currently favor Biden by 13 points, while suburban men are about evenly divided.

Biden leads by 20 points among White voters with college degrees while Trump leads by 22 points among White voters without college degrees. Four years ago, Trump won non-college White voters by more than 30 points.

Women back Biden by 56 percent to 40 percent, about the same as their margin for Clinton over Trump in 2016. Men currently favor him by half that margin — 51 percent to 43 percent — though they went for Trump in 2016, according to exit polls.

Black voters support Biden by 87 percent to 9 percent for Trump. That margin is just shy of Clinton’s winning margin among Black voters in 2016, and farther behind Barack Obama’s 95 percent support in 2008 and 93 percent support in 2012, with Biden as his running mate.

The Post-ABC poll was conducted Aug. 12-15 among a random national sample of 1,001 adults, with 75 percent reached on cellphones and 25 percent on landlines. Overall results have a margin of sampling error of plus or minus 3.5 percentage points; the error margin is four points among the sample of 868 registered voters, and it is larger among other subgroups.