The outgoing chairmen of the House and Senate Appropriations committees are set up for a bountiful swan song as a sprawling $1.3 trillion fiscal 2018 omnibus spending bill comes to fruition this week.

For Senate Appropriations Chairman Thad Cochran, resigning April 1, it’s a “mic drop” moment as the ailing 80-year-old Mississippi Republican will walk off the stage just after the omnibus measure is expected to become law. Cochran’s departure leaves his state with an enormous loss of clout that he will be anxious to ameliorate in his final go-round.

Mega-projects in play include a massive and controversial Mississippi River flood control plant that was killed off a decade ago by President George W. Bush’s EPA, and money to keep Pascagoula shipyards in the hunt for a contract worth up to $3 billion to build the first new polar icebreakers in four decades.

House Appropriations Chairman Rodney Frelinghuysen is retiring at the end of the session, and theoretically the New Jersey Republican has one more bite at the apple with fiscal 2019 spending bills. But Democrats salivating at the chance to retake the House in November may calculate that they can shape final appropriations more to their liking by delaying until next January.

That makes fiscal 2018 omnibus priorities, such as funding for the $30 billion Gateway Program of bridge and tunnel projects in New York and New Jersey, all the more important.

A Look Back at Sen. Thad Cochran’s Congressional Career

“I can tell you [Cochran and Frelinghuysen] both enjoy a tremendous amount of goodwill, not just with the Republicans but the Democrats … my suspicion is because of all that goodwill [other lawmakers are] going to want to take care of them,” said James Dyer, a former Republican staff director of the House Appropriations Committee.

Going for the gusto

It’s the first time both House and Senate appropriations chairmen are stepping down in the same year since 2005, when House Appropriations Chairman C.W. Bill Young of Florida and Senate Appropriations Chairman Ted Stevens of Alaska faced term limits on their chairmanships. But both Republicans stayed in Congress for several more years, including as influential Defense Appropriations Subcommittee chairmen or ranking members.

Grabbing federal dollars with gusto wouldn’t be without precedent, as Appropriations chairmen have been known to top off long careers by going out big.

In early 2009, Senate Appropriations Chairman Robert C. Byrd gave up the gavel due to health reasons, much like Cochran is doing. With much of the spadework on appropriations done the prior year on the fiscal 2009 omnibus, the West Virginia Democrat — who once called himself the “Big Daddy” of bringing home money for local projects — secured $362 million worth of earmarks, a 15 percent jump from the prior year. Overall discretionary spending rose by less than 9 percent.

Fiscal 2009 was also a year of plenty for Byrd’s successor as chairman, Sen. Daniel K. Inouye, who once called himself the “No. 1 earmarks guy” in Congress. Putting the omnibus to bed under his watch, the Hawaii Democrat included $390 million in earmarks, a nearly 11 percent hike from fiscal 2008. That’s a tempting prospect for the likely incoming Senate Appropriations Chairman, Richard C. Shelby of Alabama, who is no stranger himself to bringing home the bacon.

Watch: Ryan Wants Omnibus Done ‘As Fast as Possible’

Earmarks by another name

In the no-earmark era — the practice was banned after Republicans took back the House in November 2010 — it’s more complicated to figure out the value of federal funding for lawmakers’ states or districts. But that doesn’t mean lawmakers don’t take credit for provisions in spending bills that will ultimately trickle down to their constituents.

For Frelinghuysen, the future of Gateway could mean the difference between epic traffic jams or smooth commutes for the 77 percent of his constituents who drive to work by themselves, according to Census Bureau data. In a September press release touting the inclusion of $900 million for Gateway in an initial House-passed fiscal 2018 appropriations package, Frelinghuysen said the program was important not only to the New York-New Jersey area but “critical to our nation’s economy.”

The Trump administration opposes Gateway funding in the omnibus package. Stripping the funds would be a serious affront to the outgoing chairman, but could be seen as retribution for his vote last year against the Republican tax code overhaul. Frelinghuysen opposed the measure’s $10,000 annual cap on state and local tax deductions, because his constituents pay relatively high taxes.

Other funds Frelinghuysen inserted into the House spending bill include:

• $50 million for Homeland Security Department nonprofit security grants, which President Donald Trump proposed to eliminate, including for New Jersey synagogues subjected to bomb threats last year
• A $354 million increase over Trump’s initial request for Superfund hazardous waste cleanup, or $28 million above the previous year’s appropriation. New Jersey is home to more Superfund sites than any other state, Frelinghuysen said
• A $300 million increase for NIH cancer research, of benefit to the Rutgers Cancer Institute of New Jersey, among other facilities.

Yazoo pump, polar icebreaker

Cochran is also using his final appropriations bill to try to secure long-sought priorities for his home state.

The Senate’s draft fiscal 2018 Defense appropriations measure contains $150 million to accelerate procurement of a heavy polar icebreaker, a contract for which Pascagoula-based Huntington Ingalls Industries and VT Halter Marine are in the running.

The joint Navy-Coast Guard project — which would get an additional $19 million in the draft Senate Homeland Security spending bill — envisions awarding the first new icebreaker contract in fiscal 2019, with delivery in 2023. Two more ships are expected after that, to replace the current aging fleet as the U.S. struggles to compete with Russia, with its 46 polar icebreakers and 15 more in development, for supremacy over Arctic waters.

That’s not the only shipbuilding project at stake: Cochran is also pushing for $1 billion the White House did not request, to build a next-generation amphibious warship manufactured by Huntington Ingalls.

Another provision would directly benefit farmers in Cochran’s home state: a provision tucked into the Senate’s draft fiscal 2018 Interior-Environment bill would direct the U.S. Army Corps of Engineers to allow construction of a disputed flood control project on the Mississippi River, first authorized in 1941.

The EPA killed the $220 million Yazoo Backwater Area Pumps project in 2008 under the George W. Bush administration because of damage the pumps would cause to wetland and aquatic resources.

Another complicating factor for today’s chairmen is that behind the scenes, projects and priorities requested by Appropriations chairmen can sometimes compete against the will of powerful of Senate and House leaders, not to mention the president.

There’s also the unpredictable dynamic in Washington that if the political tide shifts, sometimes an outgoing chairman’s swan song can fall on deaf ears — a prospect Frelinghuysen is no doubt well aware of as the fiscal 2019 appropriation season beckons.

Take former Sen. Barbara A. Mikulski, a onetime Appropriations chairwoman, then ranking member, who retired after the 2016 elections. With a new consolidated FBI headquarters set to be built in Maryland or Virginia, the Maryland Democrat secured a $390 million down payment in the fiscal 2016 omnibus. Mikulski and her successor, Democrat Chris Van Hollen, helped win an additional $523 million in the fiscal 2017 omnibus enacted last May, and what they thought was a commitment for more in fiscal 2018.

But Trump canceled the replacement project in July. And his administration added fuel to the flames with a proposal to demolish the FBI’s current headquarters at the J. Edgar Hoover Building and rebuild it in the same Washington, D.C., location.

While expressing concern about the abrupt about-face in committee report language, GOP appropriators in both chambers have nonetheless proposed to offset some unrelated fiscal 2018 costs with a $200 million rescission of prior-year funds for the FBI headquarters project.