The GOP controls 245 seats in the 435-member House and 54 in the 100-seat Senate. And while the Senate's rules give Democrats plenty of ways to block bills, many of the most important fights will pit Republicans against Republicans.
"There are certainly blocks within the Republican Party, but you also have to include the Democratic minority in the Senate as a factor," said Josh Holly, a principal at the Podesta Group and former communications director at the House Armed Services Committee. "These factions create very little room for error for leadership in getting enough votes. When you need 218 to pass legislation in the House, and 60 in the Senate, there's little room for error."
Some see an example for future bills in the Department of Homeland Security funding fight, which was sparked by the GOP's far-right faction insisting a DHS appropriations bill include policy riders targeting the White House's recent immigration action.
With the GOP factions jockeying for position and the Senate's Democratic minority doing the same, it could be difficult to move legislation such as annual Pentagon spending and authorization bills to final votes.
"The DHS situation shows that getting the votes for cloture on appropriations won't be an easy task," Holly said. "It's a real balancing act."
Collender warned in a Feb. 17 blog post that "the Republican vs. Republican budget war is now wide open for all to see." He warns of House "intransigence" matched by Senate "unwillingness" to go along.
Collender also sees an "unwillingness" from Senate Democrats "to provide any votes for their GOP colleagues even on issues where there is some agreement." And the DHS showdown, he wrote, "has backed Republicans so far into a political corner that it's not at all clear how they will fight their way out."
A February 11, 2015 photo shows the US Capitol with its dome encased in scaffolding as it undergoes renovation in Washington, DC. The White House revealed to lawmakers on Tuesday details of its request to Congress for a three-year war authority to battle Islamic extremists that would prohibit "enduring" offensive combat operations. AFP PHOTO/MANDEL NGAN (Photo credit should read MANDEL NGAN/AFP/Getty Images)
Photo Credit: MANDEL NGAN / AFP/Getty Images
The result: Spending bills still stall in the upper chamber. And that could leave the 2016 defense appropriations bill, like others before it over the last six years, sitting idly on the Senate docket as the fiscal year draws to a close.
One faction involved is Republican defense hawks. And a recent Gallup poll indicated the American people are shifting to their side, with a growing number saying the Pentagon budget is too small.
Fifty-six percent of all Republicans polled by Gallup said the United States spends "too little" on its military, compared with 17 percent of Democrats. Independents fell in the middle, at 33 percent.
Notably, the nonpartisan polling firm said 34 percent of all those surveyed answered "too little," the highest amount since 2001. Thirty-two percent believe the US is spending too much on the Defense Department.
The firm also asked those surveyed to assess the strength of the US military. "Not strong enough" was the answer for 44 percent, with 42 percent replying "about right" and 13 percent answering "stronger than it needs to be."
Still, there is little evidence two months into the new Congress that lawmakers are ready to respond to one poll by increasing defense spending caps.
But, according to a GOP defense source, "what I'm interested to watch is what Republicans do … on the firewall between defense and nondefense spending" set up by the 2011 Budget Control Act.
As the Budget committees go about their complicated work, congressional defense appropriators are looking for a way to pass a 2016 Pentagon spending bill before the fiscal year ends.