Corey Gilgannon/The New York Times

“I served this country as a U.S. marine, and now I got to watch it go down the tubes because we let anybody in, without no rhyme or reason,” said Jim Behan, 67, as he stood on West 72nd Street holding up a large sign with the words, “Illegal Immigration — No Order, No Border, No Nation.”

Mr. Behan wears battle fatigues. After all, he is truly in the trenches here in this Upper West Side hub, where many disagree with his hard-line “close the borders” view. He says he gets more than his fair share of nasty comments from passers-by.

“Oh, you wouldn’t believe the things they say — it’d curl your hair,” he said at the spot on Saturday afternoon. “‘You’re the reason this country’s in such bad shape.’ They absolutely hate me. But my opinion is, there’s no order at our borders, and it’s ruining us as a country. I’m upset that our leaders have not enforced the laws of our country, and Obama’s going to be a disaster.”

Mr. Behan lives a block away, in a furnished room on West 71st Street, and his $70-a-week rent is regulated by state law. He said he was a New York City employee, first for the Department of Sanitation, and later for the Department of Transportation, on the Staten Island Ferry. Now he lives on a partial pension and Social Security, he said, and spends many days holding up his sign to enlighten the naïve Upper West Siders.

“Yeah, you got mostly liberals up here, but I do get some people who say, ‘I agree with you,’” said Mr. Behan, who wore a shamrock-insignia pinky ring.

He said his parents were born in Brooklyn, both the children of Irish immigrants. They raised him in College Point, Queens, where they owned a bar and restaurant where he worked, he said.

“They walk by and give me the finger –- my own people, the Irish,” he said.