DEMOCRATIC presidential frontrunners Bernie Sanders and Pete Buttigieg came under sustained attacks during a debate on Friday night as rivals raised questions about their ideology and experience.

The debate was the eighth and perhaps most consequential in the Democratic Party’s year-long quest for a presidential nominee.

It came just four days after Iowa’s caucuses – and four days before New Hampshire’s primary – with several candidates facing pointed questions about their political survival.

Former vice president Joe Biden questioned Sanders’s status as a democratic socialist and said Buttigieg, the 38-year-old former mayor of South Bend, Indiana, does not have the background to lead in a complicated world.

Senator Amy Klobuchar of Minnesota, who is struggling to break into the top tier, echoed those comments.

But Sanders and Buttigieg, who essentially tied for first in the Iowa caucuses, largely brushed off the criticism.