A majority of New York City voters continue to disapprove of Mayor Bill de Blasio’s job performance, according to a Quinnipiac University poll released on Monday, but he would still probably fare well in a matchup against at least two of his potential Democratic primary rivals.

The poll results also showed that New Yorkers’ perceptions of Mr. de Blasio remain starkly divided along racial lines, with 75 percent of black voters viewing the mayor favorably, compared with 27 percent of whites. Among Hispanics who were polled, 52 percent had a favorable opinion of Mr. de Blasio.

The telephone survey, of 1,310 New York voters, was conducted from July 21 to 28, with a margin of sampling error of plus or minus 2.7 percentage points.

The results were similar to an earlier Quinnipiac survey conducted in mid-May. In the latest poll, 51 percent of those surveyed said that they disapproved of the way that Mr. de Blasio was handling his job, while 42 percent approved. In the May poll, 52 percent disapproved and 41 percent approved. Those poll results were a departure from a survey in January, when 50 percent said they approved of his job performance while 42 percent disapproved.