Before anything can be done the budget has to be balanced. So I'm assuming, and we know how that goes, that that 60% balances the current budget leaving 40% to pay down debt and/or distribute back to taxpayers.
There's that 'priority' that the budget be balanced.
You are talking your self out of extending tax cuts which expire this year if you adhere to that mantra.
In fact, if it is such a priority to pay down debt, why not raise taxes to do so?
If you don't want to do that, it isn't 'the priority', is it?