President Biden on Wednesday asked Congress for a massive infusion of funding to overhaul the nation’s power grids and expand renewable energy as part of a landmark program designed to fight climate change and expand American jobs.

The estimated $2 trillion American Jobs Plan, if enacted by a split Congress, would be the most ambitious federal investment program to date to fight global greenhouse gas emissions and address economic inequality. The president, who campaigned in part on moving toward a clean energy economy, is casting the proposal as a major jobs program as it works to build union support.

The deal also is pitched as a way to compete against the growing might of China.

“The president’s plan will unify and mobilize the country to meet the great challenges of our...