The tone of the Democratic race has sharpened as the candidates head to New York. Bernie Sanders has won seven of the last eight nominating contests, but early polling shows he faces a big challenge in New York.

The latest Emerson poll shows Hillary Clinton with an 18 percentage point lead. While the poll shows Sanders gaining on Clinton compared to the last Emerson poll, it is a considerable step back from more recent polls showing Sanders as close as 10 percentage points to Clinton.

The Wyoming caucus takes place Saturday, April 9 then it is on to New York for the April 19 primary.

Clinton and Sanders have exchanged words this week over who is “qualified” to win the nomination. Citing a Washington Post article questioning his qualifications, Sanders asked whether Clinton is qualified for the nomination earlier this week.

Sanders criticized Clinton on the Iraq war, ties to Wall Street fundraising and their disagreement over trade deals. The two will have the opportunity to discuss these issues and others in next Thursday’s CNN Democratic debate. Clinton has denied she questioned Sanders qualifications.

There are 247 delegates at stake in the New York primary and the delegates are divided proportionally based on the results.

Here’s a look at the latest New York Democratic polls.

Emerson

The Emerson poll was conducted April 6-7. It has a margin of error of 5.4 percentage points.

CANDIDATE VOTE% Hillary Clinton 56 Bernie Sanders 38

RealClear Politics Average

RealClear Politics keeps a running average of the New York polls. The polls include data from two polls. The CBS News/YouGov poll conducted March 29-April 1 and the Quinnipiac poll conducted March 22-29.

CANDIDATE VOTE% Hillary Clinton 53.5 Bernie Sanders 42.5

CBS News/YouGov

The CBS News/YouGov poll was conducted March 29-April 1. It has a margin of error of 5 percentage points.

CANDIDATE VOTE% Hillary Clinton 53 Bernie Sanders 43

Quinnipiac

The Quinnipiac poll was conducted March 22-29. It has a margin of error of 3.7 percentage points.