Kirk's critics accuse him of having a "racial blind spot."
"Senator Kirk, re-assess your thinking. Do the right thing," Illinois State Representative Lisa Hernandez, (D) Cicero, said.
The Latino lawmakers are stunned that Illinois U.S. Senator Mark Kirk sided with his most conservative colleagues in a failed vote that would have stopped immigration reform.
"For a representative from the state of Illinois, this is unconscionable," Cook County Commissioner Jesus Garcia said.
Kirk's Washington office issued a statement that read in part, "require border security first and then proceed with other reforms."
"I have not had a conversation with him about why he voted that way or the rationale for it so I am not about to speculate," IL Rep. Tom Cross, (R) Oswego, said on Wednesday.
Illinois Republicans who support immigration reform are also surprised by Kirk's vote.
"Strategically, I think it's an evolution process for him and for his policy," Elmwood Park Mayor Angelo "Skip" Saviano, (R), said.
Earlier this year, the North Shore republican angered African American politicians when he suggested the mass arrest of 18,000 gang members.
"Is there something about Senator Kirk where he doesn't respect minorities?" Ald. Danny Solis, 25 th Ward, said.
"He's coming out in the interest of black Americans," Charles Butler, internet talk show host, said.
Conservative activist Charles Butler rejects the charge that Senator Kirk has a "racial blind spot". He says the Illinois senator should focus on stopping millions of new, undocumented workers.
"How will that impact black Americans and poor Americans trying to get a job? Negatively. There is no upside to immigration legal or illegal for black Americans," Butler said.
Alderman Danny Solis said he cannot understand why Senator Kirk--who suffered a major stroke in 2012--did not learn from the experience to have compassion for others in need.
"Maybe his recovery is not quite there yet. I don't know," Solis said.
In his statement, Kirk said he would vote for the immigration reform if an amendment for strengthened border security was added. At least one such amendment was rejected by the chamber Thursday afternoon.
There's no word yet on how that might impact senator kirk's position.