Lying about Obama's Budget
According to Republicans, Obama's proposed budget greatly increases the deficit. As you can see, Obama's budget does indeed increase the deficit, versus the CBO baseline (green line), which represents current law.
That is because under current law the Bush tax cuts would expire. The CBO also projects the expected real-world deficit knowing that in the real-world the Bush tax cuts will be extended. The reddish-brown line is the actual baseline, unless anyone beieve the Bush tax cuts will be allowed to expire. The Obama budget deficit is considerably lower than the real-world expected deficit.
Put another way, the real comparison is Obama (blue line) versus business as usual (brown line). The green line doesn't mean anything, unless the entirety of the Bush tax cuts expire.
It is a pity that the Republican candidates budget plans are not scored here because every one of them would have a vastly higher deficit. I would guess that Santorum's budgetary plans would create a defecit higher than during World War II.
Long story short:
1. Obama budget plans offer, by far, the lowest deficit of anyone running for president.
2. The only reason the Obama budget "increases" the deficit is the planned extension of the Bush tax cuts, which is supported by all Republicans.