This is undeniably false.
In 2011, we spent $78B on the SNAP program alone (source:
http://www.cbo.gov/sites/default/files/cbofiles/attachments/04-19-SNAP.pdf). With total spending of $3.6T in 2011 (source:
http://en.wikipedia.org/wiki/2011_United_States_federal_budget), that's 2.2% of the federal budget.
So, if we consider food stamps to be the only welfare program (which is an unbelievable stretch), the number presented by mother jones is barely 1/5 of the size of the actual number.
Mother Jones' own site cites a study in a different article that shows that we spend roughly $1.8B per year on welfare programs (
http://www.motherjones.com/kevin-drum/2012/02/how-much-do-we-spend-nonworking-poor). Taking out social security and medicare, which I would rather not debate even though they technically are wealth transfers, we are talking about roughly $700B, which would be about 20% of the federal budget.
tl;dr = mother jones says mother jones is wrong by more than a a factor of 10, possibly a factor of 100 depending on how you define a welfare program. Good mythbusting.