It’s been a long ten months for the climate change bill.

Last June, House Speaker Nancy Pelosi (D-CA) navigated the controversial measure through the rocky House shoals and to a narrow legislative victory. She declared the package her “flagship issue.” Then the bill set sail for the Senate. Which on Capitol Hill can be the equivalent of dispatching a bill down the River Styx.

The bill has drifted for nearly a year in the Senate. Out of Pelosi’s hands, it was no longer a flagship. But downgraded to a sloop or a lugger. No wind blew through its sails. No tide carried it to shore. The bill was lost at sea.

But last week, Admiral Pelosi again peered through her sextant. Things were looking up. Top White House environmental adviser Carol Browner indicated the legislation was “doable” this year in the Senate. And Sen. John Kerry (D-MA) worked with Sens. Joe Lieberman (I-CT) and Lindsey Graham (R-SC) to unveil the Senate’s version of the package. By Wednesday, Pelosi firmly had hold of the helm and declared the legislation “the flagship issue of this Congress.”

By Thursday, Admiral Pelosi had already downgraded the climate bill to just another boat in Congress’s legislative fleet. The speaker indicated she wouldn’t impede the Senate from taking up an immigration reform bill before it tackles the climate package.

“If the Senate is ready with an immigration bill, we don’t want anybody holding it up for any reason,” Pelosi said. “Send it to us.”

And by Saturday night, the legislation was already in dry dock. Graham, whose sponsorship of the bill is viewed as crucial to lure other Republicans, dropped out of talks. That forced Kerry and Lieberman to postpone the planned rollout of the plan Monday.

“Regrettably, external issues have arisen that force us to postpone only temporarily,” Kerry said in a statement.

Graham punted because he believed Senate Majority Leader Harry Reid (D-NV) and Pelosi were reorganizing the fleet and reflagging immigration reform as the next big issue in Congress.

“This has destroyed my confidence that there will be a serious commitment and focus to move energy legislation this year,” Graham wrote.

The South Carolina Republican said that designating immigration reform as the lead issue “is nothing more than a cynical, political ploy,” he added.

Reid responded that he was “committed” to passing a climate change bill by the end of the year. He added that he would not permit one bill to be played off against the other.

So why the Congressional switcho-chango?

Late last week, Arizona’s governor signed into law the nation’s harshest immigration law. It allows police to detain and question suspects who they believe could be illegal immigrants. That’s sent some key Democratic lawmakers into full battle mode. Rep. Luis Gutierrez (D-IL) has been cooling his heels with a big immigration reform bill for months. Last December, he introduced a bill to secure “our nation while fixing our broken immigration system.” Gutierrez has been waiting in the wings with his measure since completion of the health care bill. In fact, he had serious reservations about the health bill because it didn’t address the issues of illegal immigrants and health care. Meantime on Saturday, Rep. Raul Grijalva (D-AZ) suggested an economic boycott of the state to apply pressure on Arizona Gov. Jan Brewer (R) to rescind the new law.

In short, the immigration issue has been simmering for years. Democrats are well aware of the nation’s changing demographics and know that they need to court Hispanic and Latino voters. So that could account for the legislative juggling.

Still, time is waning on this year’s calendar. Despite Democrats’ insistence they can handle both the climate bill and immigration reform, it’s important to note which measure they tap first for action.

And if it comes down to it, picking one bill over the other could have electoral consequences for Democrats. For instance, the House has already approved its version of the climate bill. And Senate Democrats would have to rely on GOP support. Or lean on the likes of Sen. Blanche Lincoln (D-AR) who face tough re-election campaigns this fall. Meantime, if the climate bill never sees the light of day in the Senate, that could hang out to dry many House Democrats who took tough votes on the bill. Reps. Rick Boucher (D-VA), Zack Space (D-OH), Frank Kratovil (D-MD) and many others took tough votes on that legislation and face competitive elections in the fall. Those who lose will know that supporting that legislation, without Senate action, was the equivalent to walking the plank on Pelosi’s vessel, flagship or not.

Last Wednesday, Pelosi said that she “looked forward to working with the Senate soon and sending this legislation to the president’s desk.” She later said that lawmakers were “energized” about this bill. On Thursday, John Kerry issued a statement saying “we can’t afford to wait and we’ll never have as clear a shot to reach this goal we first set out 20 years ago.” And on Sunday, tens of thousands crowded the National Mall on the 40th anniversary of Earth Day. Sting,  John Legend and “Avatar” director James Cameron spoke.

The throng was concerned about global climate change. But it was clear the political climate on Capitol Hill had changed. Almost overnight. Kind of like in the apocalyptic film “The Day After Tomorrow” where a superstorm plunges the Earth into an ice age in a matter of days.

So immigration reform is at the front of the legislative line for now. The political climate’s evolved. And the question is whether this is temporary? Or whether the change in the political climate is driving the climate legislation into a long, deep parliamentary freeze that it won’t emerge from for years.