New York City’s Democratic mayoral primary field is crowded, diverse and tenacious, like the city itself. It includes candidates who would be the first woman, the first Muslim and the oldest person elected to lead City Hall. As the race has heated up, the contenders have traversed the five boroughs in an effort to gain support from millions of voters who hold competing interests and visions of New York.

Running for citywide office, like much of American politics, is a contact sport. Candidates seeking to raise money and boost their name recognition have had to take their message directly to voters — meeting them everywhere from the seats of the G train to the steps outside an N.B.A. playoff game at Madison Square Garden. And that was just before the first debate.

Candidates often campaigned in places where they had personal connections, or sought out New York City icons like the Cyclone roller coaster and the Staten Island Ferry.

Yet the dark political mood has cast a shadow over the contest. All the Democrats running have made big promises to bring the city they love back. Rising costs of living, threats from President Trump and enduring concerns over public safety have captured New Yorkers’ attention and are driving their votes. This atmosphere has prompted some of the candidates who currently hold public office to leverage their positions to make waves and force tough policy conversations.

The race coincides with continuing tensions within the Democratic Party, which is still forging a path forward after bruising losses in last year’s presidential election. And as the candidates seek to galvanize voters and make a name for themselves, they have also sought to paint themselves as fighters for their city, and against Mr. Trump. Here are some moments captured by New York Times photojournalists of the leading candidates on the campaign trail.

Adrienne Adams