I have mentioned Professor Michael Pettis in the past, a new article from him in Foreign Affairs which touches on some of this:The reality is this (with rounded numbers):
-$1T on interest that isn't negotiable
-$1.2 T on military
-$3T on healthcare (medicare + ACA)
-$1.5T on SS
-$800 billion on literally everything else
$2T deficit
If you go back to pre Bush tax rates you raise $0.5-1T (maybe... we're still not out of the 2008 recession and this could be the straw that breaks the camel's back).
You can't balance the budget without repealing Obamacare subsidies to employers. It's literally not possible.
So the answer to your question is whenever we pass sweeping healthcare reform. You have to view GOP fiscal policy over the last 15 years as purposefully forcing that decision.
A Great Rebalancing Is Coming
Who will bear the costs of a global trade adjustment?
The trade imbalances that have come to characterize the global economy are fundamentally untenable. China, Germany, and a handful of other economies run large, persistent trade surpluses, while the United States absorbs much of these surpluses by running the world’s largest trade deficit. Sooner or later, something must give. For an advanced, capital-rich economy such as that of the United States, an enduring trade deficit will bring with it either rising unemployment or rising debt, neither of which is sustainable.