Navigating ongoing rifts on the political left, US Democratic Party Chairman Tom Perez says party unity is crucial in the fight against President Donald Trump, whom he lambasted as an “existential threat” to the nation.

“We have the most dangerous president in American history and one of the most reactionary Congresses in American history,” Perez said on Saturday as he addressed the first national party gathering since his election in February.

The former Obama Cabinet officer blistered “a culture of corruption” that he said extends to Trump’s Cabinet, House Speaker Paul Ryan and Senate Majority Leader Mitch McConnell.

But Perez also warned that internal ruckuses over party priorities and leadership would distract from the goal of winning more elections to upend Republicans’ domination in Washington.

The chairman’s plea comes amid a rift over his appointments to little-known but influential party committees and the 75 at-large members of the national party committee.

Perez and his aides plug his choices as a way to make the DNC younger and more diverse, but the moves also mean demotions for several prominent Democrats who backed Bernie Sanders over Hillary Clinton in last year’s presidential primaries and then supported Minnesota Rep. Keith Ellison over Perez in the postelection race for party chairman.

-AAP