Two new national presidential polls show Donald Trump ahead as Hillary Clinton’s lead continues to narrow, although his lead in one of the polls is within the margin for error.

Furthermore, combined battleground state polling on September 18 showed the race is tied, according to CBS News. “The race across the combined battlegrounds is as tight as can be, tied 42 percent to 42 percent,” said CBS of the swing states. Read specifics on recent battleground state polls here.

However, a third poll, by NBC News/SurveyMonkey, released September 20, shows Clinton with a 5 percent lead. That’s an online poll, however.

A new Florida poll released on September 19 showed Clinton with only a 1 percent lead – again in the margin for error – in the pivotal state of Florida.

When you boil it all down: Clinton’s support continues to erode, but, since she was ahead before in most polls, the race has basically tightened to a virtual tie in many polls but with Trump achieving a lead in the last two.

The polling trend drawing great interest, though: One of the new national polls showed a dramatic increase in black support for Donald Trump. According to The New York Post, Trump “saw a 16.5 percentage-point increase in backing from African-American voters in a Los Angeles Times/University of Southern California tracking poll.” That’s up from 3.1 percent on Sept. 10 to 19.6 percent through September 16.

Trump has struggled to earn black voter support in polls in the past, although he has made a concerted effort to connect more with African-American voters, by attending a black church and making comments directed at them. In fact, a higher percentage of Hispanics supports him than African-Americans, the LA Times/USC poll shows. However, because Trump dominates Clinton among white voters, earning just some additional non-white voting support could be crucial.

Clinton’s collapse in that poll started the day of her health problem at the 9/11 memorial, The Post says.

Clinton has consistently shed support in September. How has the recent unrest – terrorist attacks, shootings of police – affected the race? The first poll to measure the period of time encompassing the day of the Chelsea explosion in Manhattan shows Trump with a 7 percentage point lead.

However, the RealClearPolitics polling average still has Clinton with a 0.9 percent edge in all national polls from September 5 to September 18. That’s a slide downward, though, for the former secretary of state, especially since the Democratic National Convention.

When you consider the margin for error, the race is basically a dead heat. Clinton led in the five previous polls, although three of those polls were in the margin for error.

Here’s what you need to know about the most recent national presidential polls, as of September 19:

Fox News

CANDIDATE VOTE Trump 46% Clinton 45%

The Fox News poll was conducted September 11 through September 14. It measured likely voters.

However, Clinton is up by one percent in this poll if you count Libertarian Gary Johnson and Green Party candidate Jill Stein.

In both cases, the leads are within the margin for error.

NBC News/SurveyMonkey

CANDIDATE VOTE Clinton 50% Trump 45%

The NBC News/SurveyMonkey poll surveys voters online. The poll was conducted from September 12 through 18 says Clinton has regained momentum against Trump, although the other two most recent polls showed the opposite.

LA Times/USC Tracking

CANDIDATE VOTE Trump 48% Clinton 41%

The LA Times/USC daily tracking poll was conducted September 12 through September 18. It’s the first poll to capture the period of the Chelsea explosion in New York and mall stabbing attack in Minnesota.

In addition to the dramatic increase in support for Trump among black voters, the poll found a large shift in the number of people who think Trump could win the race. Previously, according to The Los Angeles Times, most people thought Clinton would win the election, but now her lead is in the margin for error.

CBS News/New York Times

CANDIDATE VOTE Clinton 46% Trump 44%

This poll was conducted from September 9 through September 13. It’s a dead heat if you include Johnson and Stein.

Economist/YouGov

CANDIDATE VOTE Clinton 46% Trump 44%

This poll was conducted September 10 to 13. The margin between the two candidates remained the same in this poll if you include Johnson and Stein.

Quinnipiac

CANDIDATE VOTE Clinton 48% Trump 43%

This poll was conducted from September 9 through September 13. However, this poll also shows a narrowing of Clinton’s support because she led by 10 points in the same poll on August 25.