The Obama administration is extending the agency review period for the Keystone XL oil sands pipeline, potentially delaying the decision until after the November elections -- sparing President Obama a tough political decision in the process.

A senior State Department official said agencies have stopped crafting comments because a Nebraska Supreme Court decision could change the pipeline route and, ultimately, the environmental, socioeconomic and cultural factors that went into the environmental review. The official did not directly answer a question whether an altered pipeline route would require a new environmental review.

"The key thing that we need to better understand is whether the current route will still pertain," said the official, who did not commit to a timeline for a final decision on the pipeline. "Then we will have to make a judgment as to whether additional work needs to be done."

The Nebraska Supreme Court isn't supposed to rule on the Keystone XL route for several months. Republican Gov. Dave Heineman approved it through a 2012 state law that a lower court struck down in February.

That likely puts a final decision after the midterms, meaning Obama won't anger his environmental base by approving Keystone XL or jeopardize the re-election prospects for a handful of vulnerable Senate Democrats by rejecting the Canada-to-Texas pipeline.

The pipeline, whose builder, TransCanada Corp., must secure a cross-border permit from the State Department to finish the northern leg, is under an interagency review that was supposed to wrap up in May. State said, however, that it's continuing to process 2.5 million public comments that will be used to determine whether Keystone XL is in the national interest.

Republicans slammed the move Friday, saying it underscored what they characterized as a politicization of the Obama administration's handling of the $5.4-billion pipeline.

They have increasingly pointed to billionaire climate activist Tom Steyer, who has risen to become the left's answer to the conservative Koch brothers, as holding sway over Democrats and the administration on Keystone XL and other environmental policies.

"It’s disappointing that the president today chose to further pander to his extreme environmental donor base over the 10 million jobless Americans looking for work," Sen. John Thune, R-S.D., said of the move regarding the pipeline, which has been under review for more than five years.

Business groups and some labor unions support the pipeline, saying it will add jobs — the State Department says 42,000 direct and indirect jobs during a two-year building phase — and energy security.

Obama, however, has downplayed the jobs figure, alluding to State estimates that Keystone XL would provide 35 permanent jobs once completed.

Steyer wrote an open letter Thursday announcing "support" for lawmakers who sign a "Courage Pledge" to oppose the pipeline. The former hedge fund manager has made opposing the pipeline his key aim in a range of climate initiatives.

He has said he would donate $50 million of his own money to his San Francisco-based NextGen Climate Action PAC, with hopes of raising a matching amount, to use in this year's races and beyond.

"NextGen Climate will continue to stand up for politicians and leaders who have the courage to stand up to special interests, like Big Oil, who are in this fight for their own bottom line," Steyer said in a statement about the Keystone XL delay.

But several Senate Democrats running for re-election in red-leaning states have been looking for an assist from the White House on Keystone XL, viewing its approval as a potential boost for their electoral chances.

Last week, 11 Senate Democrats sent Obama a letter urging him to green light the project. Six of them -- Mary Landrieu of Louisiana, Mark Begich of Alaska, Mark Warner of Virginia, Mark Pryor of Arkansas, John Walsh of Montana and Kay Hagan of North Carolina -- are in tight campaign battles this year.

Another, Sen. Mark Udall, D-Colo., didn't sign the letter and has not taken a stance on the pipeline.

“Today’s decision by the administration amounts to nothing short of an indefinite delay of the Keystone Pipeline. This decision is irresponsible, unnecessary and unacceptable," Landrieu said.

Brad Dayspring, a spokesman with the National Republican Senatorial Committee, suggested the move could have implications for Democratic Senate candidates Alison Lundergan Grimes in Kentucky and Michelle Nunn in Georgia.

"Bad news for Landrieu/Pryor/Begich/Walsh/Grimes/Nunn," he tweeted Friday.

House Democrats are feeling the heat as well. Terry O'Sullivan, president of the Laborers' International Union of North America, rallied his members in 27 congressional districts held by Democrats to ensure those lawmakers feel the union's "power and fury" over Keystone XL, which it wants approved.

But environmental groups and allied donors are looking to back lawmakers who take a stand against the pipeline. They say it will facilitate oil sands growth that contributes to climate change, though a State Department environmental report downplayed that scenario.

Obama said in a June speech that he would reject the pipeline if it exacerbates carbon pollution. Environmental groups note that the State environmental report concluded that would happen if the pipeline were built.

"Whether President Obama makes a decision on the pipeline next month or next year, Keystone XL clearly fails the president’s climate test. This delay shows that TransCanada will not succeed in bullying their way to approval, bypassing established democratic procedures," said Ross Hammond, senior energy and climate campaigner with Friends of the Earth.