Hillary Clinton is leading Donald Trump 47-43 in one of the last Washington Post-ABC News tracking polls before Election Day. Post Polling Director Scott Clement explains the poll and voter demographics. (Elyse Samuels/The Washington Post)

Hillary Clinton maintains a narrow four-point advantage over Donald Trump in the Washington Post-ABC News Tracking Poll, with the Democrat holding key advantages on election eve even as pockets of uncertainty persist.

The poll, which finds 47 percent of likely voters support Clinton while 43 percent support, with Gary Johnson far behind at 4 percent and Jill Stein at 1 percent, was conducted among 2,220 likely voters from Thursday through Sunday. When third party candidates are excluded, Clinton’s margin ticks down to three points, 49 to 46 percent.

The latest Washington Post-ABC News tracking poll shows Donald Trump and Hillary Clinton in a dead heat nationally. (Peter Stevenson/The Washington Post)

Clinton’s edge in the Post-ABC poll does not reach statistical significance given the poll’s 2.5 percentage-point margin in sampling error around each candidate’s support, although a lead of this size would be a comfortable margin on Election Day. The 47 to 43 percent margin is identical to her edge in the previous four-day wave as well as a mid-October Post-ABC poll. Her margin is also the same size as Barack Obama’s winning margin against Mitt Romney in 2012, 51 to 47 percent. The final Post-ABC Tracking Poll that year found Obama at 50 percent and Romney at 47 percent.

[Read the full poll results]

The Post-ABC Poll's large sample size allows for a look at Clinton and Trump's support across a wide range of voting groups, displayed in the chart below from the Post's graphic team and interactively on this page.

The poll finds three key advantages for Clinton heading into Election Day, including early voting, widespread support among racial and ethnic minorities and historically high support among white college graduates. Yet Trump continues to fare better in key battleground states than nationally. The nearly 1 in 10 likely voters (nine percent) who do not support either Clinton or Trump lean slightly more Republican than Democratic; their support and turnout are less certain.

More than one-third of likely voters (36 percent) say they’ve already voted, up from 28 percent in the final 2012 Post-ABC Tracking Poll. Clinton maintains a double-digit advantage in support from these voters (55 to 40 percent) in the last three nights of interviewing; in 2012, Obama led by 52-46 among early voters in the Post-ABC poll and a similar margin in the national network exit poll.

Nonwhite voters support Clinton by a 72 to 19 percent margin over Trump, a 53-point advantage that is narrower than Obama’s 61-point margin over Romney four years ago. White voters support Trump by 53 to 38 percent, less than Romney’s 59-39 margin in 2012.

The largest shift in vote support from 2012 is among white college graduates, a group Democrats have not won at the presidential election in any contest since at least 1980. Clinton leads Trump by 49 to 40 percent among this group, fueled by a 56-36 percent margin among white women with college degrees. Trump nearly balances out those losses with a large, 34-point lead among all white voters without college degrees (63 to 29 percent), a group Romney won by a 25-point margin four years ago.

In Trump’s corner, he holds a 49 to 42 percent advantage among likely voters who live in one of six key battleground states: Colorado, Florida, North Carolina, New Hampshire, Nevada and Ohio. Recent state-level surveys suggests each of these states is a tossup heading into Election Day.

This Washington Post-ABC News poll was conducted by telephone November 3-6, 2016, among a random national sample of 3,218 adults including landline and cell phone respondents. Overall results have a margin of sampling error of plus or minus two points; the error margin is plus or minus 2.5 points among the sample of 2,220 likely voters. Sampling, data collection and tabulation by Abt-SRBI of New York.