J. Scott Applewhite/AP

Keystone Debate Will Test New Senate GOP Majority

Pipeline and immigration fights will headline a week that ends with party retreats.

The Senate will see a lot of firsts this week.

The debate over authorizing the Keystone XL pipeline will officially begin on Monday with the chamber's first vote in this Congress to proceed on major legislation. The motion will need 60 votes, but that will be easily accomplished: Six Democrats cosponsor the bill and three others have supported it in the past.

The debate will also be Majority Leader Mitch McConnell's first crack at managing an institution that has been racked with rancor over the past four years as Republicans and Democrats squabble over debate procedures. McConnell has pledged to allow a free and open amendment process, making a clear distinction from the practices of then-Majority Leader Harry Reid when Democrats ran the Senate. But the new Republican majority is still figuring out how that will work.

The intention is clear, even if the logistics are foggy. "Americans will now see the Senate voting on American issues. You'll be able to see where they stand on the issues of the day," Sen. Roger Wicker, R-Miss., said last week, adding that Republicans will not "shield members from tough votes" by shutting off the amendment process.

"Hold us to that," Wicker added. "Ask us about it in a month. Ask us about regular order."

A climate-change amendment will likely be the centerpiece of the political messaging machine and a key test of McConnell's pledge to allow open debate. Sen. Bernie Sanders, I-Vt., is expected to offer an amendment that would state definitively that climate change is real and caused by human activity. Republicans who are on record disagreeing with that statement will become a useful tool for environmentalists who want to make the case that the GOP isn't recognizing science.

In the wake of a White House veto threat over Keystone, attention is also turning toward finding enough votes to override it—an unlikely scenario but certainly one that Keystone supporters can aim for. Pro-Keystone Sen. Joe Manchin, D-W.Va., said he hopes the Senate will approve some Democratic amendments that will lure more supporters on final passage. "I'm looking forward to it," he said.

Democrats are plotting amendments that would bar the export of oil shipped on the Alberta-to-Gulf Coast tar-sands pipeline, require that its materials and labor are provided by Americans, and invest in clean-energy jobs.

The House passed its own Keystone bill on Friday, more than a dozen votes short of the two-thirds majority needed to override a veto.

The week in both chambers is likely to be cut short as Republicans head to Hershey, Pa., for joint retreat. The Republican event officially begins on Wednesday afternoon, which means the last votes in both chambers will likely take place early in the day. Democrats will hold their own issues conference in Baltimore on Thursday.

Before they leave town, however, House members are slated begin a fiery debate over immigration as leaders schedule a vote on a measure to fund the Department of Homeland Security. That bill includes language to withdraw funding from President Obama's executive action to defer deportations for up to 5 million undocumented immigrants.

It's not clear what, if anything, what the House legislation will accomplish. Funding for DHS runs out at the end of February, and Senate Republicans have made it clear they have no intention of cutting off its budget. Senate GOP leaders haven't yet decided how to respond to the House bill, although they agree with House Republicans in their belief that Obama acted out of the bounds of his authority in creating the massive deportation deferral program.

Defense

Senate Republicans are expected to move soon on an Iran sanctions bill, though timing on that proposal is dependent how the Keystone debate proceeds. Talks between Iran and the United States, the United Kingdom, France, Germany, Russia, and China to give Iran relief from sanctions failed to meet a late November deadline. Under that deal, Iran would limit its nuclear program in exchange for relaxing the sanctions.

But Republicans, and some Democrats, worry that Iran doesn't intend to uphold any potential deal. Sens. Mark Kirk, R-Ill., and Robert Menendez, D-N.J., are expected to introduce a proposal to increase sanctions against Iran if talks fail. The proposal had support from a majority of senators during the previous Congress.

Lawmakers also are mulling a bill authorizing military force for the fight against ISIS. Before the holiday break, Secretary of State John Kerry pledged to work with lawmakers to help come up with a proposal. The administration, unlike some in Congress, wants no restrictions on the potential use of ground troops.

Henry Kissinger, the secretary of State for Presidents Nixon and Ford, will testify Tuesday in the Senate Armed Services and Foreign Relations committees.

Senate Armed Services also is expected to hold a confirmation hearing for Ashton Carter to be the next Defense secretary in early February.

Health

The Senate Health, Education, Labor, and Pensions Committee is preparing for a hearing this month on Republican legislation to change the Affordable Care Act's definition of "full-time" work from 30 to 40 hours per week, weakening the health law's employer mandate. The measure passed the House Thursday, but fell short of a veto-proof majority. McConnell says he is determined to hold a vote on the bill in the Senate, but timing on that debate is unclear.

Technology

In the wake of North Korea's alleged hack of Sony Pictures, the House Foreign Affairs Committee will hold a Tuesday morning briefing to examine the threat the nation poses to the United States. Officials from the State, Treasury, and Homeland Security departments are set to testify.

White House

President Obama faces a busy week during which he will mix foreign policy with a continuation of his domestic travel to preview themes he will hit in his upcoming State of the Union address. On Monday, he will go to the Federal Trade Commission to talk about identify theft and privacy issues. On Tuesday, he and Vice President Joe Biden will meet with the Republican and Democratic leaders of the House and Senate. He will then go to the National Cybersecurity and Communications Integration Center to discuss cybersecurity threats. On Wednesday, he goes to Waterloo, Iowa, for a speech about affordable, high-speed broadband access. Thursday, he is scheduled to go to Baltimore to attend the Senate Democratic Issues Conference. That night he will have dinner with British Prime Minister David Cameron. With Islamic terrorism, Ukraine, trade and ebola on the agenda, Friday he will meet in the Oval Office with Cameron.

Jason Plautz, Jordain Carney, Sophie Novack, Brendan Sasso, Daniel Newhauser, Sarah Mimms and George E. Condon Jr. contributed to this article.