Rory Reid may have a problem.

In the most recent poll, the Democratic nominee for governor seems to be struggling to catch up to Republican Brian Sandoval—and it may be too late.

A new Public Policy Polling survey Mr. Sandoval leading Mr. Reid 52 percent to 38 percent with 11 percent undecided. The poll was conducted July 16-18.

Mr. Sandoval, a former state Attorney General and federal judge, is viewed favorably by 42 percent and unfavorably by 31 percent with 27 percent undecided. On the other hand, Mr. Reid, son of Senate Majority leader Harry Reid, is viewed unfavorably by 48 percent and favorably by 34 percent, with 18 percent undecided.

Mr. Reid continues to lead in voters who describe themselves as moderates (47 percent of the sample) by 48 percent to 38 percent, with 14 percent undecided. Mr. Sandoval holds 81 percent to 10 percent of conservatives.

The former Clark County commissioner has struggled in recent months to raise his support. Earlier polls had Mr. Reid at a similar disadvantage, which many political analysts say is partly the result of the senior Reid’s unpopularity.