President Obama’s second inaugural address was a ringing affirmation of Democratic priorities and a resolute defense of federal safety-net programs. But there’s little chance that the president will be able to move his second-term agenda through Congress unless and until Washington stops its relentless, all-consuming bickering over the federal budget.

For the sake of his own aspirations, Obama should focus on something he paid scant attention to in last Monday’s speech: persuading Democrats and Republicans to agree on a plan to pare the deficit and bring the national debt under control.

The president’s approach so far has been to take modest positions on the budget publicly while pushing for a “grand bargain” in private negotiations with House Republican leaders. His annual budget submissions to Congress have been notably light on ways to slow the growth of entitlements or shore up Social Security for the long run — vital elements of any deal with Republicans. The president’s role in the budget is limited, given that the Constitution gives Congress control of the federal purse. And administration officials have argued that when presidents take the lead in budget talks, their proposals become lightning rods for criticism and impede a deal.

Obama should lead a Democratic push for reforms that preserve the safety net programs for those who need them, while also reducing the deficit and stopping the federal debt from growing faster than the economy.

He’s in the best position to lead on this issue, able to provide political cover for Democrats concerned that their constituents won’t put up with changes to the status quo, while showing Republicans that there are ways to save money without abandoning the government’s commitment to the elderly and poor.

To create an opening for the rest of his agenda, he needs to step up to that role.