As I posted on another thread:

"There is just no wiggle room. The Republicans did it."

http://zfacts.com/p/1170.html

Don't hesitate to follow links to the real data.
Please check the calculations yourself using the spreadsheet.
Yes, it was Reagan and Bush 1.
Forget about Bush 2 and Obama (although Bush 2's undfunded wars make up the next biggest burden).
If not for Reagan-Bush tax cuts and spending increases, we would not be where we are today.