In the calm between election seasons, Congress has a fleeting chance to enact overdue immigration reform.

With strong bipartisan support, the Senate passed reform legislation in June. President Barack Obama, who needs to deliver on his own promise of reform, believes the House has the votes to do something similar.

Traditional Republicans want GOP House members to fix the system's flaws. And unless Republicans act, their efforts to win over Hispanic voters are doomed.

Outside the bubble of electoral politics, comprehensive reform -- with better border security, tighter workplace enforcement, rational legal immigration and a way out of the shadows for people here illegally -- would be a plus for national security, the economy and the rule of law.

In New York City alone, state Comptroller Thomas DiNapoli said last week, immigrants accounted for $210 billion in economic activity in 2011 -- or about 31 percent of our gross city product.

Yet plenty could go wrong on the road to reform.

The biggest obstacle is what to do about the estimated 11 million here illegally. The Senate would give them provisional legal status and a tough 13-year path to citizenship. That's a nonstarter for many House Republicans and some Democrats. But if a path to earned citizenship is ideal, legalization without it is a reasonable alternative.

Lawful permanent residency would all but eliminate the risk of deportation. It would let people work on the books, pay taxes and travel to their native countries. Unlike citizens, they couldn't vote, or petition for parents, siblings and married children to immigrate here. And their legal status wouldn't necessarily be irrevocable. Still, it's not a bad deal. But there are hurdles.

Some Democrats may want the issue around to use against Republicans in 2014 and beyond. Some GOP House members represent districts where voters adamantly oppose legalization. Such problems could prove fatal.

Congress once allowed real differences to be honestly aired, followed by compromise and majority rule. That's how it should work now.