Our position on immigration is the same as the Church's, which is summed up in 2241 of the Catechism:

The more prosperous nations are obliged, to the extent they are able, to welcome the foreigner in search of the security and the means of livelihood which he cannot find in his country of origin. Public authorities should see to it that the natural right is respected that places a guest under the protection of those who receive him. Political authorities, for the sake of the common good for which they are responsible, may make the exercise of the right to immigrate subject to various juridical conditions, especially with regard to the immigrants' duties toward their country of adoption. Immigrants are obliged to respect with gratitude the material and spiritual heritage of the country that receives them, to obey its laws and to assist in carrying civic burdens.

There is some leeway in interpreting this passage. The Church's position is nuanced, obliging us to be generous but at the same time upholding the State's right to enforce rule of law.

The problem comes when Bishops make Immigration their #1 priority. Considering all the problems in the Church, the fact that this is even on the Bishops' radar right now is disturbing. Furthermore, the Immigration issue is causing bishops to make inroads with the political enemies of the Church.

The reason the bishops are making common cause with our enemies and focusing on this largely political issue is because instead of trying to minister to fallen away Catholics, they seek the easy path and are trying to bolster their pews and tithes with illegal immigrants. This strategy is doomed to failure however, since illegal immigrants leave the faith at an even faster rate than Native US Catholics.

The bishop is not wrong when he says we have an obligation to foreigners and to share the wealth of our country (from a Christian understanding, not a socialist one). But that's incidental to the real issue.

What's wrong here is that many bishops aren't interested in actually helping the poor immigrants. They are doing the right thing the wrong way for the wrong reasons, by jumping in bed with the Party of Death for money. And in doing so, they are ignoring the massive problems facing our Church, problems they can actually solve and have viable solutions.