It’s simply a hostage exchange. The Republicans gave up the fiscal cliff, and will now take the debt limit, the federal budget and automatic across-the-board cuts to discretionary spending (the sequester), and have another standoff in 2-3 months time. The deal wouldn’t have gotten 85 GOP votes in the House without the leadership giving right-wingers ironclad guarantees that they’ll have another hostage soon.
What leverage will the White House have at that point? They’ve already rejected the “constitutional option” to avoid the debt ceiling — and won’t mint a big platinum coin. The Bush tax cuts on high earners will be off the table. That leaves cuts to defense — which Republicans hate — and public opinion, to which the GOP doesn’t seem terribly responsive when its base is screaming murder and threatening primaries (which is always). That’s pretty thin gruel given that the “austerity caucus” thinks it has a good shot at cutting Social Security and Medicare as part of a “grand bargain” with Obama.
Other than that, we’ll only have the Democrats’ legendary iron back-bone on which to rely. Nobody’s ever gotten rich betting on that.