As President Obama huddles today with Senate Democrats on his $3.7 trillion budget proposal, the Congressional Black Caucus is emerging as one of the loudest House Democratic critics of a plan that Marc Ambinder at National Journal calls "The Budget Nobody Likes."

In his press conference yesterday, Obama insisted that "just like every family in America, the government has to do two things at once: It has to live within its means and it has to invest in the future." He compared the budget to the balancing act many families must make when they decide to cut back on eating out and other luxuries in order to save for their kids’ educations.

Yet, several House Democrats, including CBC members, have disagreed. A spokesperson for Rep. Jesse Jackson, Jr.–who sits on the House Appropriations Committee, where the real fight with GOP deficit hawks will be engaged–criticized the president’s analogy, saying, "It isn’t cutting luxuries, it’s cutting things that are vital."

CBC Chair Emanuel Cleaver agreed in a harshly worded statement reacting to Monday’s budget. "Rebuilding our economy on the backs of the most vulnerable Americans is something that I simply can not accept," Cleaver said. "I understand that now is the time for us as a nation to sacrifice in order to protect our children from a mountain of debt; however, I am struggling to understand how this budget helps us to best achieve this critical goal."

Obama’s choice to attack the deficit by cutting community development funding and home heating assistance, among other programs, will almost certainly have disproportionately negative effects on blacks and Latinos, who are twice as likely to live in poverty as the rest of the population.

On the House floor yesterday, Rep. Jackson railed against Obama’s choices. "In the midst of the worst economy most of us have ever seen, we are cutting the legs of the unemployed, the underemployed and the economically insecure out from under them."

Jackson and other House members see Monday’s budget as an extension of last year’s tax cut deal. "Our point has been that the real problem is the tax cut deal that was launched in December," says Jackson spokesperson Andrew Wilson. Jackson argues that the deal Obama made with Republicans in order to get unemployment benefits extended has had consequences for the deficit, which now leads to cuts that affect the "poorest of the poor, those who are unemployed, those who are stuck in failing schools."

That unemployment deal extended the Bush-era tax cuts–including cuts for the richest people in the country–and will add $858 billion the deficit. That $858 billion has now become part of Obama’s balance sheet, something he has to grapple with as he makes what he called "difficult choices" about budget cuts.

Conventional wisdom is that the White House knows this budget proposal is pure positioning–the president gets to define himself as a responsible spender, and Democrats can restore the unpopular cuts during the messy process of actual appropriations.

But Republicans are in the process of drafting a budget proposal that makes Obama’s look wildly generous. Which is why Jonathan Cohn at The New Republic says that, while Obama’s budget is just an opening bid, he’s concerned about the outcome:

You could make a case that, by embracing the Republican narrative on the size of government and calling for a five-year budget freeze at present levels, Obama has effectively bid too low in the negotiation over federal spending–that he’s committed himself, and the country, to less government than it needs. (It’s happened before!) Or you could make the case that, by making "tough" proposals to cut programs he supports, he’s establishing the credibility with voters that he needs in order to marginalize the Republicans and to preserve more spending than might otherwise be possible. (It’s happened before!)

I really don’t know which argument is right. I’m not a political strategist and, besides, not even the political strategists can be sure about this sort of thing. But I know I’ll be hoping that Obama prevails in the coming standoff with House Republicans, even though a victory would still leave the government perilously underfunded.

But with Obama willing to cut programs at the outset that disproportionately affect poor folks and people of color, it seems likely that whatever budget the president and Congress eventually agree upon will be most damaging to the most vulnerable.