[citation needed] Seliger is currently a member of the National Rifle Association of America, the Texas Farm Bureau, and the Harley-Davidson Owners Group.

Seliger was sworn into the Texas Senate on March 2, 2004, to complete the term of Teel Bivins of Amarillo, who obtained a diplomatic appointment as United States Ambassador to Sweden from the administration of U.S. President George W. Bush.

The district spans twenty-six counties and serves large slices of the Panhandle and Permian Basin, including Amarillo, Midland, Odessa, and Big Spring.

[4][failed verification] Seliger was appointed by Lieutenant Governor David Dewhurst to serve as Vice-Chair of the Criminal Justice Committee for the Seventy-ninth Texas Legislature.

As the vice chairman of the Senate Criminal Justice Committee, Senator Seliger passed House Bill 2577 requiring local law enforcement agencies to report to the state the reason for a peace officer's termination to protect the integrity of the state's law enforcement officers.

Seliger's membership on the Senate Natural Resources Committee aided him in passing several important bills for West Texas.

The Texas Municipal League presented Seliger with its 2005 Distinguished Legislative Service Award for his dedication to protecting and promoting local control.

Seliger won re-nomination to a full four-year term in the state Senate in the Republican primary held on March 4, 2014.

[7] In 2019, he was the sole Republican in the Senate to oppose a religious refusals bill, commenting, "When you're the only Jew on the floor ... it’s a different shade on your opinion.

They included Midland oil businessman Kevin Sparks and Big Spring steel business owner Stormy Bradley, who is also a school board member.

[9] On January 22, 2019, Seliger was removed as chair of the Texas Senate Agriculture Committee after suggesting that a female staffer at the Capitol in Austin kiss his posterior.