Sen. Susan Collins (R-Maine) will take over as the head of the extremely influential Senate Appropriations Committee after Republicans take power in January, succeeding Sen. Patty Murray (D-Wash.) in the powerful position.

“As chair of the senate appropriations committee, my priorities will remain helping Maine’s communities, funding biomedical research to save and improve lives, improving our infrastructure, supporting rural economic development, and helping to strengthen our workforce by supporting education, job training, and childcare programs,” said Sen. Collins.

Sen. Mitch McConnell (R-Ky.), the most senior senator on the committee, has announced that he plans to chair the smaller Senate Appropriations Subcommittee on Defense.

That leaves the chairmanship of the full committee open to be filled by the current vice chair, Collins.

The Appropriations Committee wields enormous power over the operations of the U.S. government, with the ability to determine how much funding, if any, will go to most federal programs and agencies.

“The Appropriations Committee, through the annual appropriations bills, then decides how much funding each authorized federal government agency and program receives, effectively determining which can operate and to what extent,” says the committee’s website.

The committee does not have authority over federally mandated funding for programs such as Medicare, Social Security, and interest payments on the growing national debt.

According to the committee website, those expenditures accounted for 72% of federal spending in 2023.

The success of many of President-elect Donald Trump’s proposals could rely on approval from the committee for necessary funding, including the funds needed to carry out a mass deportation program.

As head of the Appropriations Committee, Collins will be in a position to either significantly help or significantly hinder President Trump’s agenda.

Since Trump’s controversial cabinet began to form, Collins has stood with the Republicans most resistant to his agenda.

She openly opposed Trump’s plan to use recess appointments, which were used by President Barack Obama, and President George Bush, to install his cabinet picks without lengthy confirmation hearings.

She also expressed skepticism over Trump’s public health picks, including his proposed Department of Health and Human Services (HHS) Secretary, Robert F. Kennedy Jr.

Collins was also among the Republicans who stood against Trump’s first choice for Attorney General, former Rep. Matt Gaetz (R-Fla.), eventually leading him to withdraw his name from consideration for the position.