A friend of mine recently linked me to The Cato Journal's Winter 2012 edition which is dedicated to the subject of immigration.  While I have not yet read all of  these articles, the few I have read look good and they are definitely pro-migrant.  You may want to check them out.  Here's a summary of the contents:

Is Immigration Good for America?

James A. Dorn
Editor's Note
(PDF, 2 pp., 33Kb)

Daniel T. Griswold
Introduction: Is Immigration Good for America?
(PDF, 4 pp., 49Kb)

Bryan Caplan
Why Should We Restrict Immigration?
(PDF, 20 pp., 177Kb)

Gordon H. Hanson
Immigration and Economic Growth
(PDF, 10 pp., 95Kb)

Giovanni Peri
Immigration, Labor Markets, and Productivity
(PDF, 20 pp., 175Kb)

Joel Kotkin and Erika Ozuna
America's Demographic Future
(PDF, 16 pp., 140Kb)

Stuart Anderson
America's Incoherent Immigration System
(PDF, 14 pp., 126Kb)

Pia M. Orrenius and Madeline Zavodny
The Economic Consequences of Amnesty for Unauthorized Immigrants
(PDF, 22 pp., 196Kb)

Edward Alden
Immigration and Border Control
(PDF, 18 pp., 151Kb)

Jim Harper
Internal Enforcement, E-Verify, and the Road to a National ID
(PDF, 14 pp., 117Kb)

Margaret D. Stock
Is Birthright Citizenship Good for America?
(PDF, 20 pp., 164Kb)

Daniel T. Griswold
Immigration and the Welfare State
(PDF, 16 pp., 147Kb)

Raúl Hinojosa-Ojeda
The Economic Benefits of Comprehensive Immigration Reform
(PDF, 26 pp., 219Kb)

Joshua C. Hall, Benjamin J. VanMetre, and Richard K. Vedder
U.S. Immigration Policy in the 21st Century: A Market-Based Approach
(PDF, 20 pp., 174Kb)

(H/T to MB)