MADISON, Wis. — President Joe Biden said Monday that more than 30 million borrowers would see “life-changing” relief from his new plan to ease their student loan debt burdens, a fresh attempt by the Democratic president to follow through on a campaign pledge that could buoy his standing with younger voters.

He detailed the initiative, which has been in the works for months, during a trip to Wisconsin, one of a handful of battleground states that could decide the outcome of Biden’s likely November rematch with Donald Trump, the presumptive Republican nominee.