What is worse? 20% across the board income tax cut or cutting medicare by 716 billion?

[SamuelRSmith]

Tigerlure said:

Dark_Lord_2008 said:
Both policies sound like reasonable measures to reduce the deficit spending and kick start the lagging American economy. Why not adopt both policies?

Because adding to the deficit by passing huge tax cuts isn't a good idea for the economy in the long term. 

Why not?