He was defeated in his bid for re-election by Ciro Rodriguez, a former Democratic member of Congress, in a special election runoff held on December 12, 2006.

He graduated from South San Antonio High School in 1972 and received his Bachelor of Journalism degree from the University of Texas at Austin in 1976.

Bonilla was inadvertently assisted by the state legislature, which left a heavily Republican area of western San Antonio in the 23rd while carving the new 28th District out of much of the 23rd's territory.

Largely because of his popularity in San Antonio, he did not face a credible challenge until 2002, when Democrat Henry Cuellar, a former Texas secretary of state, came within two points of unseating him.

When Bonilla took charge in 1999 of an independent political fund called American Dream PAC, he made clear that its mission was to "give significant, direct financial assistance to first-rate minority GOP candidates".

[citation needed] Bonilla was priming for a rematch against Cuellar in 2004, but in 2003, a controversial mid-decade redistricting by the Texas legislature, the results of efforts by U.S. House Majority Leader Tom DeLay, moved most of Laredo, which had been one of the cores of the 23rd since its formation, to the 28th district.

In its place, Bonilla received several heavily Republican San Antonio suburbs that had previously been in the nearby 21st district, all but assuring him of a seventh term.

Soon after the 2004 elections, Bonilla was criticized when he proposed a procedural rule change that would permit House leaders to retain their leadership positions despite having been indicted by a state grand jury.

[2] The proposal would have allowed Tom DeLay to remain as Majority Leader despite having been indicted by the Travis County district attorney's office for possible campaign finance violations.

[citation needed] The justices held that as a result, the new district didn't have enough Latinos to pass muster under the Voting Rights Act.

Federal Election Commission records show Bonilla paid the Los Angeles-based law firm of Latham & Watkins $100,000 in 2006, from his campaign funds, to argue that the district boundaries were constitutional.

[4] On November 7, Bonilla faced six Democrats, including Ciro Rodriguez and Vietnam War veteran Rick Bolanos in the all-candidate special election required by the court decision on redistricting (see above).

[5] Bonilla was the first Republican incumbent in Texas to be unseated by a Democrat in 10 years, since Nick Lampson's defeat of Steve Stockman in a 1996 runoff election.

In a year of war, illegal immigration issues, and a proposed border fence, Latinos left the Republicans side in droves.