It's important for Obama to make this point, because raising the debt ceiling isn't necessarily a popular thing to do. Voters, hearing the word "debt," tend to think it's about politicians spending more money. That's why politicians in the opposition party -- among them then-Senator Barack Obama in 2006 -- tend to vote against debt-ceiling hikes to score a cheap political point against the president. Obama hopes that by explaining that the money has already been spent -- and pinning the blame for that on a Congress that's all talk when it comes to actually cutting government spending -- he can change that calculus.
But the ephemeral political advantage of demagoguing the debt ceiling disappears as soon as the government actually shuts down and/or defaults, something for which the public appears prepared to blame Congress, and especially Republicans in Congress. Thus you have Obama hammering on the consequences of debt-ceiling inaction: "If congressional Republicans refuse to pay America's bills on time, Social Security checks and veterans benefits will be delayed. ... It would be a self-inflicted wound on the economy. It would slow down our growth, might tip us into recession. And ironically it would probably increase our deficit."
Obama continued to insist he won't negotiate over the debt ceiling, which congressional Republicans see as their most significant point of leverage in the upcoming trio of fiscal deadlines. The White House's thinking is that he can simply continue to say, "Do your job," to Congress when and if they come to him seeking concessions in exchange for it, and refuse to have any further conversation.
That's a bit difficult to believe, as a couple of Obama's questioners in the White House press corps pointed out. First, debt-ceiling hikes have historically been packaged with larger fiscal deals between presidents and Congress. Second, Obama has often drawn supposed lines in the sand before only to negotiate them away -- take the fiscal-cliff deal, less than a month old, in which the president abandoned his supposedly ironclad promise not to preserve Bush-era tax rates for incomes over $250,000. And third, given that the debt-ceiling deadline coincides with the double deadlines for sequestration and budgeting, it will be difficult for Obama to negotiate over one without negotiating over the other.
Nonetheless, in vigorously explaining the debt ceiling and setting out his position, Obama is playing a more aggressive political game than he has in the past. With the formidable power of the bully pulpit on his side, he's trying to ensure that the debate over the debt ceiling stays on his terms -- a conversation about whether Congress can get its act together -- rather than allowing Republicans to turn it into a conversation about government spending.