SAN ANTONIO -

Democratic state Rep. Pete Gallego has defeated U.S. Rep. Quico Canseco in one of the most closely watched U.S. House races in Texas.

Canseco was in his first term representing the 23rd Congressional District, which now covers a huge swath stretching from just east of El Paso to San Antonio.  

Canseco won his seat in the 2010 Republican takeover of the House fueled by tea party supporters.  

But in a race seen as a toss-up, Canseco lost to Gallego, a state representative from the West Texas town of Alpine. Gallego was first elected to the Texas Legislature in 1990. 

The Associated Press called the race for Gallego just before midnight Tuesday. Rep. Gallego released the following statement:  

"As a kid who grew up in a small town of 6,000 people, having the opportunity to represent 700,000 people in Congress is truly unbelievable. Growing up in West Texas, I have a bit of an independent streak. My practice has always been to vote in the interests of the people at home. That will not change. I intend to fight for every constituent - not just those at one end of the political spectrum or other. Together, we will be an example for the rest of the country. This campaign has already been a long journey, but now the real work begins.  It's time to get to work so that all families can have a shot at the American dream, not just a privileged few. It's time to recognize that small business is the backbone of the American economy."

Canseco told his supporters late Tuesday night he wasn't ready to concede until every vote is legally and properly counted.

"This is a tight race. It's a real nail-biter," Canseco said. So as predicted, we're still up there looking for the other counties to come in. So bear with us, OK?"

In Bexar County, Canseco defeated Gallego 51 to 44 percent.

KSAT's Jessie Degollado contributed to this report.