Public debt is caused by policies, not dates.
The policies of conservative business executives, added to Bush's policies designed to pay for his holy wars, and his reluctance to tax his friends and family, caused the bottom of 2009. Recovery by US government from that Great Recession has exceeded the performance of virtually all other global economies.
What has been slow, is business recovering from their lack of recognition that American workers are also American consumers. Laying off a worker and giving his job to cheap foreign labor imported here, or sending the job there, lowers demand more than it cuts labor cost.
While most of the country has learned a lot from our flirtation with conservatism, there are many unable to learn from mistakes. The GOP hopes to keep them hooked on conservative entertainment media to retain their votes. 2012 demonstrated the failure of that strategy, however Reuplicans have found no alternative to it.
End of story.