Sara Taylor, a Republican strategist, former director of political affairs for President Bush, and Stephanie Cutter, Democratic strategist and communications director for Senator John Kerry's 2004 White House run.
In the House, Bill Thomas, chairman of the crucial Ways and Means Committee and generally an avid tax-cutter, has made sceptical noises about Mr Bush's plan.
Cutter will reprise the key behind-the-scenes role that Republican operative Steve Schmidt played for the Bush administration on the successful nominations of Chief Justice John Roberts and Justice Samuel Alito.