There is a vast landscape of websites related to the federal budget deficit. In order not to reinvent the wheel, we describe here some sites that may be useful as references or complements to Widescope.
For a more rigorous understanding, one of the best sources is the Congressional Budget Office (CBO), which is a federal agency in the legislative branch of the US Government. Their primary responsibility is to provide economic data to the Congress; this includes detailed budget projections and analysis of how various policies will affect the federal deficit. In particular, they have compiled a list of budget options that can be implemented. These options are a great resource for building a Widescope budget since they describe specific policies along with their quantitative impact on the federal deficit.
Another excellent source is the Committee for a Responsible Federal Budget, which is an independent, non-partison think tank. Besides their publications, they have also started several important initiatives, including the US Budget Watch, which tracks the positions taken by politicians as related to the federal budget. They also have produced a Deficit Reduction Plan Comparison Tool and a Budget Simulator.
There are a small number of complete budget proposals made by politicians or think tanks that may be useful as references in designing a budget. Some of the budgets proposed by politicians include: