This seems a fairly unbiased site. All sorts of data and detail. Based on this Obama would raise taxes (increase revenue) $300B and McCain decrease, $1 trillion.
A tax decrease has no hope of decreasing the current deficit and McCain has no real plan to curb spending other than vague references to vetoing earmark funding.
Obama's tax increase will be needed to fund his social programs. Tax increase coupled with "peace dividend" may or may not allow for a decrease in the deficit.
Obama has said reduction of the deficit is a priority, McCain has been silent on the issue. The huge deficit run up in the last 8 years is going to a challenge for either to make much of a near term dent.
*snip*
Although both candidates have at times stressed fiscal responsibility, their specific non-health tax proposals would
reduce tax revenues by $3.6 trillion (McCain) and
$2.7 trillion (Obama) over the next 10 years, or approximately 10 and 7 percent of the revenues scheduled for collection under current law, respectively. Furthermore, as in the case of President Bush's tax cuts, the true cost of McCain's policies may be masked by phase-ins and sunsets (scheduled expiration dates) that reduce the estimated revenue costs. If his policies were fully phased in and permanent, the ten-year cost would rise to $4.0 trillion, or about 11 percent of total revenues.
Both candidates argue that their proposals should be scored against a "current policy" baseline instead of current law. Such a baseline assumes that the 2001 and 2003 tax cuts would be extended and the AMT patch made permanent. Against current policy,
Senator Obama's proposals would raise $300 billion, an increase of 2 percent, and
Senator McCain's proposals lose $1.0 trillion (if fully phased-in and permanent), a decrease of roughly 2 percent. Senator McCain has stressed that deficits should be closed by spending cuts, but policies he identifies, such as limiting earmarks, would offset only part of the revenue losses attributable to his tax plan. As noted, both candidates may be overoptimistic in their revenue targets for closing tax loopholes-Obama probably more than McCain.
A Preliminary Analysis of the 2008 Presidential Candidates' Tax Plans (Full Report): revised June 20, 2008