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

Hillary Clinton has a narrow four-point edge over Donald Trump heading into the final weekend of a campaign where 3 in 10 likely voters say they’ve already cast their ballots, according to a new Washington Post-ABC News Tracking Poll.

Likely voters currently break 47 percent for Clinton and 43 percent for Trump in interviews conducted Monday through Thursday, a lead that is within the range of sampling error and similar to Clinton’s 47-44 margin in the previous four-day wave but the largest numerical gap between candidates in the past week of daily tracking. Libertarian Gary Johnson’s support has ticked up from 3 percent to 4 percent in the latest wave, while Jill Stein stands at 2 percent, the same throughout the past week. Clinton continues to show weaknesses in the closing days. She trails Trump by five points on the question of which candidate is more honest and trustworthy, and she no longer holds a significant lead among those who have already voted nationwide. And among those who have not voted yet, Trump supporters are more likely to say they are following the contest “very closely,” suggesting they may turn out at higher rates.

[Read full poll results | Graphic: Who key groups are supporting]

But Clinton’s current 4-point edge is identical both to that found in a mid-October Post-ABC poll and to President Obama’s 4-point winning margin in 2012.

Clinton benefits from big advantages with many of the groups that fueled Obama’s two elections. African American likely voters support Clinton by 86 to 6 percent over Trump, shy of Obama’s 93-6 margin in the 2012 exit poll. Latinos favor Clinton by 71 to 23 percent, similar to a 67-19 percent margin in a Washington Post-Univision News Poll of Latino voters released Thursday and Obama’s 71-27 margin in 2012.

While the overall gender gap in Clinton's and Trump’s support is similar to past elections, the divide is particularly stark among younger voters in the latest Post-ABC Tracking Poll. Among likely female voters younger than 40, Clinton leads by 59 to 31 percent over Trump, compared with a 41 to 38 percent split among younger men. This is one area where Clinton may stand on the better end in terms of turnout, as younger women have historically turned out at higher rates than their male counterparts.

Partisans continue to support their party’s nominees at similar levels, with 88 percent of Democrats supporting Clinton and 85 percent of Republicans supporting Trump. Both of those figures are slightly lower than in previous years, in part because of the presence of third-party candidates holding significant support; candidates generally exceed 90 percent support among fellow partisans.

Independents favor Trump by 45 to 39 percent; Clinton and Trump both receive support from more than 8 in 10 independents who say they lean toward their one party, while those who lean toward neither party favor Trump by 43 to 34 percent.

Early voters

Early voting continues to climb at a rapid tick, with 30 percent of likely voters saying they have already voted, higher than the 21 percent who had voted by the end of last weekend. The current share of likely voters who report casting ballots already is higher than at the same point in the Post-ABC Tracking Poll four years ago; five days before the 2012 election, 22 percent said they had voted early.

Clinton holds only a narrow edge over Trump in support among early voters, 49 to 44 percent, similar to her edge among likely voters but smaller than the 54-41 advantage in the Post-ABC Tracking Poll early this week. While the attitudes of early voters who have already cast ballots cannot change over time, the rapidly growing size of this group can cause shifts in preferences that polls can estimate only roughly.

With turnout of chief importance in the closing days, Clinton supporters who have not yet voted are somewhat less likely to report following the race closely. The poll finds 73 percent of Trump supporters who plan to vote in the coming days say they are following the race “very closely,” compared with 64 percent of Clinton backers.

Voters also say Trump is more honest and trustworthy than Clinton by 44 to 39 percent, narrowing slightly from Trump’s eight-point edge this past weekend. Clinton trails on this question due to weaker faith in her honesty among Democrats than Trump has among Republicans, as well as independents saying by 18 points that Trump is more trustworthy than Clinton. Twenty percent of independents and 12 percent of Democrats say “neither” candidate is honest.

This Washington Post-ABC News poll was conducted on cellular and landline phones Oct. 31-Nov. 3, 2016, among a random national sample of 1,419 likely voters and has a margin of sampling error of plus or minus three percentage points. Sampling, data collection and tabulation by Abt-SRBI of New York.