A new poll shows Bernie Sanders gained support for the Democratic nomination just days after Hillary Clinton officially became the party's nominee last week.

The senator from Vermont received a 4 percent bump in a poll released by Fox News on Wednesday. Forty-one percent of Democratic respondents said they wanted Sanders as their nominee, in a survey conducted July 31-August 2. That tops the 37 percent he got in a similar poll in June, before Sanders endorsed Clinton.

Clinton, meanwhile, saw her numbers drop, defying the usual post-convention bump, at least according to this particular primary-related survey. She received 56 percent support in the latest survey, a drop from 58 percent in June.

Nearly two-thirds of Sanders-backing respondents believe the primary process was rigged.

The same poll showed Clinton's lead over GOP nominee Donald Trump in the general election grow to a 10 point margin.

The telephone survey had a 4.5 percent margin of error among Democratic respondents.