Over the past couple of weeks, Donald Trump has become the presumptive Republican nominee and Hillary Clinton has continued to inch closer to the magic number of delegates she needs to lock up the Democratic contest. Clinton continues to lead Bernie Sanders in our national tracking poll (she is up by 14 points in this week’s results).

Attention is now rapidly moving to the hypothetical match-up between the leading candidates with an emphasis on a Clinton and Trump contest. In this week’s poll, Americans are nearly split between their choice of Trump or Clinton; her margin over Trump narrows from 5 points last week to 3 points this week to 48 percent to 45 percent.

This early data indicates a very close race right now — though that may change considerably before November. Understanding, why the race is close requires a deeper look into how various demographic groups break for either candidate.

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The demographic-based analyses below are from the latest data from the NBC News|SurveyMonkey Weekly Election Tracking Poll conducted online from May 9 through May 15 among 14,100 adults, including 12,507 who say they are registered to vote.

Clinton, who was able to maintain her front-runner status throughout the Democratic primary by winning over black and Hispanic voters, continues to do extremely well among these voters over Trump. She wins black voters 84 percent to 9 percent — a 75 point gap — and wins Hispanics 65 percent to 28 percent.

Trump is the preferred candidate among white voters by 14 points over Clinton — 53 percent to 39 percent. This is up slightly from last week’s 11-point margin among white voters.

There is also a significant gender gap with Clinton beating Trump by 15 points among women, while Trump carries men by a similar 11-percent margin. Gender appears to be critical to this race already with Trump’s controversial comments about Clinton playing the “woman’s card” in order to explain her success over Sanders.

NBC News

When examining voters’ preferences by income and education, those with a high school degree or less favor Trump over Clinton by 5 points. Those with college degrees favor Clinton by 7 points. Though there are many narratives that state working-class voters — at least on the Republican side — are one of the main groups responsible for Trump’s success, overall, Americans from households who earn less than $50,000 a year favor Clinton over Trump by 20 points. Those from higher-earning households favor Trump by 5 points.

NBC News

While many people are speculating that Republican voters will ultimately end up supporting Trump, and Democrats will line up behind Clinton, a big question is where independents will place their support. At this moment, independents break for Trump 44 percent to 36 percent. This group will be heavily targeted this summer and fall by campaigns and outside groups as they will be a critical voting bloc in determining the winner.

NBC News

While political ideology correlates highly with partisanship, it is interesting to note that Clinton does much better than Trump among moderate voters. This group breaks for Clinton 53 percent to 39 percent. While those who say their political leanings are “conservative” solidly support Trump, voters who identify as “very conservative” are slightly less strong in their support of the presumptive nominee.

NBC News

In a general election, turnout is everything. However, the 2016 election is a bit more unpredictable in that what motivates key groups to support — or cast a vote against their party’s opponent — could be different with a non-traditional candidate like Trump in the race.

On the Democratic side, Clinton may need to focus her efforts on overcoming large unfavorable ratings in order to sway unaffiliated voters. The same would likely to true for Trump who holds even higher unfavorable ratings than Clinton. Tracking how these various groups break for either candidate helps give early clues into where each candidate needs to focus their campaigns in the coming months.

The NBC News|SurveyMonkey Weekly Election Tracking poll was conducted online May 9 through May 15, 2016 among a national sample of 14,100 adults aged 18 and over, including 12,507 who say they are registered to vote. Respondents for this non-probability survey were selected from the nearly three million people who take surveys on the SurveyMonkey platform each day. Results have an error estimate of plus or minus 1.2 percentage points. For full results and methodology for this weekly tracking poll, please click here.