Democratic members of the U.S. Senate are hearing new levels of criticism from liberal activists who see 'soft bigotry' in a sea of senior staffers' lily-white faces.

It's usually Republicans who bear the brunt of complaints about a lack of black and Hispanic hiring.

But the only black chief of staff in the upper chamber of Congress works for South Carolina Republican Sen. Tim Scott, the first black Southerner elected to the Senate since Reconstruction.

And it's Scott who has emerged as a leading voice on Capitol Hill diversity hiring.

Matt House, center, and other aides to Senate Democrats, are emblematic of what some diversity activists are calling a lily-white hiring culture on Capitol Hill

South Carolina Sen. Tim Scott has the only black chief of staff in the Senate, and he's a Republican who regularly offers colleagues help identifying qualified minority job hopefuls

'If you can't find a talented qualified person that diversifies your office, give me a call,' Scott told the Roll Call newspaper last week. 'I can help you find those people.'

Democrats have found themselves on the defensive.

'It's not that anybody's racist,' one staffer said. 'It's just that there's a lack of experience, there's a lack of knowledge because you don't have that set of employees sitting at the senior table.'

A group of black activist organizations has asked the six new senators – five of whom are Democrats – to prioritize hiring minorities as they build out their staffs.

Two of the three Senate Hispanics are Republicans, Ted Cruz of Texas and Marco Rubio of Florida.

The only incoming Hispanic senator, Nevada Democrat Catherine Cortez Masto, will have a senior staff that doesn't include any Hispanic women.

An illegal immigrant who advises Sen. Bernie Sanders reacted with scorn after Democrat Catherine Cortez Masto, an incoming Latina senator, unveiled a senior staff that included no Hispanic women

Immigration activist and Bernie Sanders aide Erika Andiola, an illegal immigrant herself, reacted on Facebook.

'Oh, look at all those Latinas she hired in her senior staff! A grand total of ... 0. No pos wow,' she wrote.

The result is what some consultants, activists and Black Lives Matter leaders are calling 'soft bigotry' among Democrats, reports Politico.

Hawaii Democratic Sen. Brian Schatz said his party needs 'an uncomfortable conversation' about why its hiring practices don't line up with the values its candidates boast when they campaign for public office.

'I don't think anybody is nefarious,' he told Politico. 'But we're just not getting it done.'

One former senior Democratic aide said it's 'bull***t' to cast Caucasian-heavy staffing as the product of a thin minority bench.

It's 'something a lot of people have been sounding alarm bells on for years and nothing has changed,' the former Capitol Hill staffer said.

Incoming Senate Majority Leader Chuck Schumer, a New York Democrat, is considering a push for a rule that would require senators to interview minority candidates for senior jobs.