The GOP lawmakers joined with 60 House Democrats in the letter, which also called on the panel to keep the door open for savings culled from benefit programs such as Medicare - a path opposed by many Democrats. In addition, the letter said the panel should aim for $4 trillion in 10-year savings - more than triple the panel's mandated minimum target of $1.2 trillion.
At a news conference and in separate interviews Wednesday, Republican participants shied away from expressing an unconditional willingness to accept tax increases as part of a final deal.
Even so, the letter's bipartisan, conciliatory tone contrasted with the political atmosphere in Washington that has buffeted the supercommittee, which has made little evident headway just three weeks from the Nov. 23 deadline for completing its work.
"To succeed, all options for mandatory and discretionary spending and revenues must be on the table," the letter said. "In addition, we know from other bipartisan frameworks that a target of some $4 trillion in deficit reduction is necessary to stabilize our debt as a share of the economy and assure America's fiscal well-being."
The signers constituted about one in six House Republicans and nearly a third of its Democrats. Participants said they believed that many other lawmakers also supported a large package with savings from both spending cuts and new revenue, and expressed hope that a letter signed by 100 of the House's 435 members would have clout.
The signers included many moderates from both parties, along with conservatives such as presidential candidate Ron Paul (R., Texas); House Democratic Whip Steny H. Hoyer of Maryland; and liberals such as Rep. Emanuel Cleaver (D., Mo.), who chairs the Congressional Black Caucus. Among Philadelphia-area representatives, the signers included Democrats Robert E. Andrews of New Jersey and Chaka Fattah of Pennsylvania, and Pennsylvania Republicans Charlie Dent, Michael Fitzpatrick, and Patrick Meehan.
So far on the supercommittee - which consists of six Republicans, including Sen. Pat Toomey of Pennsylvania, and six Democrats - Democrats have demanded higher taxes as their price for accepting big savings from benefit programs, while Republicans have opposed revenue increases and insist on trimming benefit programs.