This is how ATR explains things:
Washington has an overspending problem, not an under-taxing problem. Historically, outlays have averaged about 21 percent of Gross Domestic Product (GDP) while revenues have amounted to about 18 percent of GDP. Due to the Obama Administration and Congressional Democrats’ spending binge, outlays now average almost 25 percent of GDP, and are projected to stay around 23 percent in perpetuity.
Unless tax hikes are taken off the table, reckless lawmakers will increase taxes to pay for these new bloated spending levels, rather than bring spending in line with revenues. Any lawmaker serious about restoring American solvency cannot seriously vote for a BBA that does not include a super-majority requirement for tax increases. To pass a BBA that allows a tax hike by simple majority is to distract from the real problem of government spending, and leave taxpayers to bear the burden of foolhardy federal budgeting.
This would establishes a constitutionally mandated "continuing resolution" provision that would hold spending at the previous year's level until a new budget is enacted.