Earmark-Congressional directive that funds should be spent on a specific project.
Word origin-1590s, "to identify by an earmark," from earmark (n.). Meaning "to set aside money for a special purpose" is attested by 1868. Also the process of marking cattle. Earmarks got banned in 2011 after complaints about the bridge to nowhere, banned by the republican party. Congress would use this term to describe processes of allocating funds.
Logrolling- The practice of exchanging favors
Pork barrell spending is a “metaphor for the appropriation of government spending for localized projects secured solely or primarily to bring money to a representative's district. The usage originated in American English. In election campaigns, the term is used in derogatory fashion to attack opponents.”
Examples:
“One of the most famous alleged pork-barrel projects was the Big Dig in Boston, Massachusetts. The Big Dig was a project to relocate an existing 3.5-mile (5.6 km) section of the interstate highway system underground. It ended up costing$14.6 billion, or over $4 billion per mile. Tip O'Neill (D-Mass), after whom one of the Big Dig tunnels was named, pushed to have the Big Dig funded by the federal government while he was the Speaker of the United States House of Representatives.
During the 2008 U.S. presidential campaign, the Gravina Island Bridge (also known as the "Bridge to Nowhere") in Alaska was cited as an example of pork barrel spending. The bridge, pushed for by Republican Senator Ted Stevens, was projected to cost $398 million and would connect the island's 50 residents and the Ketchikan International Airport to Revillagigedo Island and Ketchikan”
Logrolling- Vote trading by legislative members to obtain passage of action of interest to each legislative member. The first known use of the term was by Congressman Davy Crockett, who said on the floor in 1835, "my people don't like me to log-roll in their business, and vote away pre-emption rights to fellows in other states that never kindle a fire on their own land."
Grand Finale: Log rolling can be used to support earmarks which can be referred to as pork barreling when it is seen as unnecessary government expenditures.