Insiders on the panel say that the deal being offered by Democrats is less than $1 of spending cuts for every $1 of new taxes. Democrats want to count the $900 billion of discretionary spending cuts already agreed to in the debt bill and $1 trillion in troop withdrawals from Afghanistan and Iraq, which may not happen. Meanwhile they are insisting on close to $1.2 trillion of tax increases in exchange for less than $1 trillion in entitlement reforms. The president’s own deficit reduction committee, Simpson-Bowles, offered $2 of cuts for every $1 of new taxes. The GOP House budget passed last spring contained some $4.5 trillion in cuts—three times more than the super committee must find…

But raising rates and raising revenues are different. Eliminating loopholes in exchange for making the Bush tax cuts permanent after 2013 is on the table—and by broadening the tax base, this could bring in tens of billions of new revenues each year. Says Mr. Hensarling: “Republicans want more revenues. We want more revenues by growing the economy; we’re not happy with revenues at 14% of GDP, but we don’t want to do it by raising rates.”

One positive development on taxes taking shape is a deal that could include limiting tax deductions, perhaps by capping write-offs on charities, state and local taxes, and mortgage interest payments as a percentage of each tax filer’s gross income. That idea was introduced on these pages by Harvard economist Martin Feldstein.

In exchange, Democrats would agree to make the Bush income-tax cuts permanent.