Former Democratic presidential candidate Bernie SandersBernard (Bernie) SandersMellman: On Political Authenticity (Part 2) Former Sanders campaign manager: Don't expect email list to be shared with DNC Adult film star: Trump and Stormy Daniels invited me to 'hang out' MORE on Sunday discouraged voters from picking a third-party nominee, saying the issues facing the U.S. are too dire for a "protest vote." 

ADVERTISEMENT
"This moment in history for a presidential election is not the time for a protest vote," the Vermont senator said on CBS's "Face the Nation." 

"It's time to look at which candidate will work best for the middle class and working families." 

He said he didn't want to disparage third-party candidates, but he encouraged voters to pick Democratic presidential nominee Hillary ClintonHillary Diane Rodham ClintonIntel Dem decries White House 'gag order' after Bannon testimony 'Total free-for-all' as Bannon clashes with Intel members Mellman: On Political Authenticity (Part 2) MORE over Republican nominee Donald TrumpDonald John TrumpDems flip Wisconsin state Senate seat Sessions: 'We should be like Canada' in how we take in immigrants GOP rep: 'Sheet metal and garbage' everywhere in Haiti MORE

Libertarian presidential nominee Gary JohnsonGary Earl JohnsonGary Johnson: Trump admin marijuana policy shift could cost him reelection When pro-Clinton trolls went after me during the election Gary Johnson: I don’t want to be president anymore ‘because of Trump’ MORE has hoped to benefit from record low favorability numbers for Clinton and Trump. But a RealClearPolitics polling average only gives him 8.9 percent support nationally.