Setting up a showdown over federal spending, the House of Representatives today narrowly passed a bill that would replace the cuts from the defense side of the trigger, part of the debt limit deal of last year, mostly with cuts to federal workers and the social safety net.

The 218-199 vote capped a day of often emotional debate and carries with it major implications for the November elections –and the fiscal crisis awaiting Congress at the end of this year.

Building on the House budget resolution in March, the 167-page bill continues an aggressive election-year rewrite of last summer’s agreements to shore up Pentagon spending without having to rely on new tax revenues. Non-defense appropriations already face $27 billion in cuts beyond what the budget law anticipated, and the new measure adds a second round of savings, culled from President Barack Obama’s signature initiatives as well as core benefit programs such as Medicaid, food stamps, and the child tax credit.

The long-term unemployed, who have swelled the food stamp rolls, are among the most vulnerable, together with single-mother households and working class immigrant families. Depressed swing states like Florida would feel the pinch, and some of the proposed cuts have been opposed in the past by that state’s young Republican political star, Sen. Marco Rubio, often mentioned as a potential running mate with Mitt Romney.

I don’t really know what Rubio’s doing in this article. But it’s true that states hit hard by the recession would be particularly vulnerable to this legislation.

The bill does not even replace all of the cuts envisioned by the trigger, which total $1.2 trillion. This $237 billion price tag only covers less than a quarter. It wouldn’t even eliminate the trigger for more than a year. But it does have a pretty major impact in the near term. The cuts would replace $55 billion in defense cuts that would take place next year. Not one Democrat supported the bill, which Republicans claim they passed through the reconciliation process, though the Senate has not initiated such a reconciliation bill. Sixteen Republicans, most of them endangered in re-election races in November, voted against it. Democrats offered a substitute to replace the defense trigger with the Buffett rule, essentially, but it failed.

Here are just some of the impacts:

The House bill would leave pending mandatory cuts in place, including cuts to Medicare. It would turn off $72 billion in cuts to both the Pentagon and on defense spending mandated by sequestration, but add $315 billion in new cuts, none of which are imposed on the Pentagon.

Under the House-approved legislation, food stamp eligibility is tightened, the Prevention and Public Health Trust Fund under the 2010 healthcare law is ended, the Federal Medicaid match to states is reduced, new stricter eligibility standards for Medicaid are imposed, and the Social Services Block Grant, which funds Meals on Wheels, is ended.

More savings come from cutting all funding for the Consumer Financial Protection Bureau, cutting federal worker pay and through medical tort reform.

The cuts would reduce the overall discretionary spending cap for 2013 by $19 billion below the level set in the debt deal.

Basically the bill throws the debt limit deal in the garbage and starts over, with spending limits below what was already negotiated. This has been a major bone of contention on Capitol Hill, and now the House is locked into a policy that has already drawn a veto threat. Something will have to give, and the solution must come by the end of the year.