From your link:

The statutory pay-as-you-go rule in place in the 1990s was a valuable tool in helping to turn then-record budget deficits into surpluses starting in 1998. However, Republicans did not renew the pay-as-you-go rule after it expired in 2002, and over the last six years this Administration and previous Congresses violated the pay-as-you-go principle by failing to offset trillions of dollars of tax cuts and new mandatory spending. During that period they oversaw the largest fiscal deterioration in history – squandering the record $5.6 trillion ten-year projected budget surplus that President Bush inherited and replacing it with record deficits and rising debt.