You know how Democrats so often talk about diversity as a goal in itself? For others anyway. Now comes a serious problem for some of their candidates seeking to tip the narrow Senate party balance in their party’s direction come Nov. 6.

In a survey done by Democrats themselves the figures reveal that some of the most endangered Senate Democratic candidates have the least diverse staffs of all.

Take Montana’s incumbent Sen. Jon Tester in a competitive reelection battle for a third term. His staff is 93 percent white.

Or West Virginia’s endangered Joe Manchin. His staff is 92 percent white, according to his party’s diversity initiative.

The most distinctly white is Sen. Angus King of Maine. Technically, he’s not a real Democrat, but he plays one 100 percent of the time in the Senate Democrat caucus.

His staff is 95 percent white with zero Latinos, zero North Africans, zero Middle Easterners, zero Hawaiians and zero Native Americans. King would point out that his staff is precisely 50 percent male and female, which is supposed to matter in his world.

Take Minnesota’s Sen. Tina Smith — 85 percent white. Her fellow Minnesotan, Amy Klobuchar, has hired a two-thirds white staff with 14 percent each black and Asians, two percent Native American and 56 percent male.

Or next door North Dakota’s embattled Heidi Heitkamp whose staff is 86 percent white with not a single black at work there.

Even some of the paragons of liberal virtue-signaling like Bernie Sanders fail a diversity exam. His staff is 82 percent white with zero Asians and zero Native Americans. But he does employ two females for every male. His fellow Vermont senator, Patrick Leahy, is not quite as attentive with an 85 percent white staff.

Those white New England Democrats do seem to have problems finding diverse staff members. Rhode Island’s Sheldon Whitehouse comes in with 85 percent while Jack Reed scores 81 percent white and no blacks.

Massachusetts’ Elizabeth Warren claims to have Native American blood. But she employs not a single Native American. Missouri’s struggling Sen. Claire McAskill has 69 percent white staff, 20 percent black but no Asians, Middle Easterners or Native Americans.

New Hampshire’s Jeanne Shaheen has 83 percent white staffers and also no Native Americans. New Mexico’s Martin Heinrich not surprisingly has a 40 percent Latino staff but employs no blacks.

Speaking of blacks, New Jersey’s Cory Booker has hired a staff that’s 22 percent Latino, 33 percent black, six percent Asian or Middle Eastern but no Native Americans.

California’s Kamala Harris, who has ambitions beyond the Senate, has a staff 26 percent each black and Latino, 14 percent Asian, 57 percent female but no Middle Easterners.