Letting these tax policies expire would level the playing field for Republicans in tax negotiations next year. Instead of being in a “box,” Republican leaders would have leverage again — something the Democrats want and would have to make concessions to get.
Going over the fiscal cliff would help the GOP in another way: It would save Republicans from having to break their pledge not to raise taxes. If GOP leaders hold the line on taxes this fall, and the Bush tax cuts expire despite their best efforts, it would not harm their reputation as the party of low taxes. But if Republicans vote proactively to raise taxes as part of a “grand bargain,” the GOP brand would be irreparably damaged. Raising taxes and losing a fight to stop automatic tax increases are two different things.
Moreover, if the Bush tax cuts expire, the baseline for future negotiations would be reset. A bipartisan agreement would be within reach that reforms and simplifies the tax code, with a top rate lower than the Clinton rate but higher than the Bush one. Instead of Republicans being under pressure to raise taxes, Obama and the Democrats would be under pressure to reduce the top rate from the Clinton level as part of an eventual deal.