WASHINGTON — No one was more critical than Representative Mark Steven Kirk when President Obama and the Democratic majority in the Congress sought passage last year of a $787 billion spending bill intended to stimulate the economy. And during his campaign for the Illinois Senate seat once held by Mr. Obama, Mr. Kirk, a Republican, boasted of his vote against “Speaker Pelosi’s trillion-dollar stimulus plan.”

Though Mr. Kirk and other Republicans thundered against pork-barrel spending and lawmakers’ practice of designating money for special projects through earmarks, they have not shied from using a less-well-known process called lettermarking to try to direct money to projects in their home districts.

Mr. Kirk, for example, sent a letter to the Department of Education dated Sept. 10, 2009, asking it to release money “needed to support students and educational programs” in a local school district. The letter was obtained under the Freedom of Information Act by the group Citizens Against Government Waste, which shared it with The New York Times.

The district, Woodland School District 50, said it later received about $1.1 million in stimulus money.