San Juan, Puerto Rico—One of the thorniest tasks awaiting a seven-member board charged by Washington with cleaning up Puerto Rico’s debt crisis is deciding how to balance a $70 billion debt load with nearly $43 billion in unfunded pension liabilities.

The issue is coming to a head now because the White House is set to name as soon as next week the members of that oversight board, drawn from lists of candidates submitted by congressional leaders in both parties.

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