LAREDO, Texas (AP) – With Democrats denouncing it as political theater but participating anyway, a Republican-led House subcommittee opened an unusual field hearing Friday near the Mexican border to discuss immigration and national security.

“It’s elementary that to defend ourselves against our determined and resourceful enemies, our border must be secure,” said Rep. Ed Royce, the panel’s chairman and a California Republican.

Rep. Silvestre Reyes, a Texas Democrat, said the hearings were about politics, not policy.

“Congress needs to get back to work in Washington to reach a compromise agreement on comprehensive border security and immigration reform legislation,” Reyes said.

Scheduled to testify later Friday at the one-day hearing were acting chief patrol agent for the Laredo border sector, Reynaldo Garza, Webb County Sheriff Rick Flores and Zapata County Sheriff Sigifredo Gonzales Jr. Both Webb County, where Laredo is located, and Zapata County are on the border with Mexico.

House GOP leaders called for hearings last month after the Senate approved a guest worker program and a possible path to citizenship for millions of illegal immigrants. A House-approved bill focuses on enforcement and has no provision for illegal immigrants or future guest workers.

The audience in Laredo was full of activists on both sides of the issue.

Rep. Ted Poe, a Texas Republican, said to cheers that if the U.S. is protecting the borders of other nations, it should also be protecting its own.

“It’s a national security issue to protect our borders from those who wish to do us harm,” he said.

Texas Democratic Rep. Ruben Hinojosa said the proceedings were a “false promise.” “This hearing will do nothing to secure our borders,” he said.

Outside the hearing, a small group of activists from U.S. Border Watch, based in suburban Houston, said there is no distinction made between illegal immigrants who come to the United States to work and live and those who come to do harm.

“Terrorists are able to use immigrants as camouflage, they blend in with them,” said U.S. Border Watch President Curtis Collier.

Also this week, Senate Judiciary Committee Chairman Arlen Specter, R-Pa., who backs the Senate bill, held a hearing in Philadelphia on the issue featuring New York Mayor Michael Bloomberg.

Bloomberg testified Thursday that the economy of the country’s largest city and the entire nation would collapse if illegal immigrants were deported en masse.

Republican-led House committees will hold hearings outside Washington in mid-July on making English the nation’s official language, and how enforcement of immigration laws affects American workers.

A hearing the week of Aug. 14 in Arizona will focus on costs to local and state governments “caused by an unsecured border.”