WASHINGTON —Three weeks into what’s become the longest full government shutdown in history, U.S. Sen. John Fetterman said he would fully endorse the idea of Republicans bypassing the filibuster rule so they could pass their spending plan without any Democratic support.

The Pennsylvania Democrat has bucked his party since the shutdown began, repeatedly voting for the GOP plan despite Democrats insisting that it include an extension of expiring healthcare credits.

But ending the filibuster would make Mr. Fetterman’s vote — or the support of any Democratic senator — unnecessary. Instead of requiring 60 votes to pass, it would allow the spending bill to pass with a simple majority.

“That would make it virtually impossible to shut it down,” Mr. Fetterman told reporters Tuesday.

Mr. Fetterma

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