The poll, conducted by Siena College in New York state, makes continuing calls and updates results in real time.
As of Friday morning, 361 likely voters had been polled with 52 percent backing Levin compared to 42 percent for his Republican opponent Diane Harkey, who is endorsed by Issa. The margin of error is 11 points.
Earlier polls have shown a closer race in the traditionally Republican district.
Levin, an environmental attorney from Orange County, is leading in fund raising, but Harkey, who serves on the state Board of Equalization, has been endorsed by President Trump.
The 49th District stretches from the UC San Diego area along the coast into south Orange County.
>> Subscribe to Times of San Diego’s free daily email newsletter! Click hereFollow Us: