Democrats' failure to effectively engage with the diverse Latino electorate had cost Joe Biden a convincing election win and control of the US Senate, former adviser Moe Vela said.

Describing his party as falling "abysmally short" of the purported blue wave of support, the former director of administration and senior adviser to Mr Biden said while he was cautiously optimistic of a Trump loss, better outreach was needed to win over more Latinos across a series of states.