Krueger was elected to the 94th and 95th United States Congresses, serving from January 3, 1975 to January 3, 1979. Krueger was initially elected to the U.S. House of Representatives to represent , then the largest congressional district in Texas, stretching from northern San Antonio to Big Bend National Park in far west Texas. In the general election, Krueger defeated Republican Doug Harlan of San Antonio, who had also run unsuccessfully against Fisher in 1972. Coincidentally, Harlan like Krueger had obtained a master's degree from Duke University. He then received a law degree from the University of Texas School of Law and became heavily involved in Republican Party consulting work. Krueger was part of the large "Watergate Class" of 1974, many of whom were Democrats who owed their election to the scandal that brought the resignation of President Richard Nixon three months before the election. Krueger was reelected for a second House term in 1976 along with the election of Jimmy Carter as president. Krueger challenged incumbent Republican John Tower in 1978 for a U.S. Senate seat from Texas, but Krueger narrowly lost the contest by 0.3%.