Cracks are showing in the Democratic coalition as the next round of budget talks gets under way, hurting the chances for progress toward a broad deal that changes the tax code and significantly narrows future deficits.

While Republicans are still smarting over nasty infighting they engaged in during the debt-ceiling fight and 16-day government shutdown, Democrats have stayed united. This helped them beat back Republican demands to undo or scale back President Barack Obama's 2010 health law as a condition for ending the showdown.

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