There are multiple sources. Here is one. I’ve also included a few other good ones. Its best to understand his position now rather than several months down the road. To me, he’s all over the place.
http://www.wausaudailyherald.com/article/20130703/WDH01/307030324/Walker-endorses-path-citizenship
http://mediamatters.org/issues/border-security
https://hotair.com/archives/2015/02/02/scott-walker-im-not-for-amnesty/
Read the quoted material in Post #37. The material the author used to construct his “GOP ideology” remark about Walker.
Now, regarding immigration - Walker has not been boxed into a corner on this. His position appears to be contemplative and we will see how he addresses this, as we all know will happen.
Keep your powder dry until it’s needed.