well he wanted something akin to a 20% reduction of income tax. And the 5 trillion figure is based on it being extrapolated over 10 years
To make it income-neutral, Romney proposes to eliminate tax loopholes but there are questions on whether that is truly feasible without expanding the deficit.
For those who didn't follow the debates, check out factcheck.org.
They go through all of the claims by both parties so it could be helpful if you had a question on what was said and its feasibility.
This post was edited on 10/5 at 12:22 pm