Comedy Central's Stephen Colbert defended himself Thursday from criticism that his scheduled appearance at a Congressional hearing on immigration Friday would "make light of a serious issue." 

"Everyone seems thrilled about it," Colbert said sarcastically during his appearance on "Good Morning America." 

Some Republican members of the committee — including Rep. Jason Chaffetz (R-Utah) — have criticized Democrats for inviting Colbert, who will reportedly testify in character as a conservative political pundit. 

"Republicans are concerned that I will make light of the responsibility of governance? That I will someway impede the smooth flow of the governing of this country? I take exception with that," he said in mock outrage Thursday. 

The hearing will be held on Friday by the House Judiciary subcommittee on immigration, which is chaired by Rep. Zoe Lofgren (D-Calif.). 

The hearing, titled "Protecting America's Harvest," will also feature United Farm Workers President Arturo Rodriguez, who had previously appeared on Colbert's show to plug the UFW's "Take Our Jobs" campaign, which invites Americans critical of illegal immigration to work as laborers in agricultural fields. 

Colbert accepted Rodriguez's offer, and worked for 10 hours on a farm in rural New York last month.

"I went out there and I worked 10 hours in the fields. And I had to stop because my doctors told me I had developed a condition known as a blister," he explained Thursday. "Blister ... Am I pronouncing that correctly? They had it lanced and bed rest for a couple of weeks and I’m right as rain."

Colbert quipped throughout his appearance on Good Morning America.

At one point, host George Stephanopoulos noted that Colbert would not be the "first fictional character" to testify in a Congressional hearing. Famed Sesame Street character Elmo, he said, had appeared before a panel in 2002.

"Then I'm in good company," Colbert replied.