The Mormon Church has issued a short statement on immigration (link). Here's why it's mostly wrong:

1. They state:

What to do with the estimated 12 million undocumented immigrants now residing in various states within the United States is the biggest challenge in the immigration debate. The bedrock moral issue for The Church of Jesus Christ of Latter-day Saints is how we treat each other as children of God.

The history of mass expulsion or mistreatment of individuals or families is cause for concern especially where race, culture, or religion are involved. This should give pause to any policy that contemplates targeting any one group, particularly if that group comes mostly from one heritage.

...The Church of Jesus Christ of Latter-day Saints is concerned that any state legislation that only contains enforcement provisions is likely to fall short of the high moral standard of treating each other as children of God.

A. They're engaging in the deportations false choice fallacy; see the link. Specifically, they're ignoring the policy of attrition whereby we'd enforce our immigration laws and reduce non-emergency benefits to illegal aliens to encourage them to leave voluntarily: no "mass expulsion[s]" would be required.

B. The "mistreatment of individuals or families" they mention can be divided into two groups: actual mistreatment, or things that aren't actually mistreatment. The first might consist of something like extra-legal detentions and the like. Various plans have been proposed to deal with illegal aliens, some of which have been struck down by the courts. However, none of those plans would involve actual extra-legal mistreatment. And, if any government entity engaged in actual mistreatment, rest assured that a team of far-left lawyers would descend like locusts to file lawsuits and issue press releases. Which leaves us with things which aren't actually mistreatment, such as enforcing our immigration laws. If the Mormon Church believes that some form of legal immigration enforcement is mistreatment, then they should work to change our laws.

C. They're engaging in a form of false compassion, in which they present enabling (at least past) illegal immigration as somehow the moral choice, when the opposite is true. The massive, mostly-illegal immigration that's occurred has had a highly negative impact on poorer American citizens, at the same time as it's hurt the people of the sending countries. Massive emigration to the U.S. helps the elites of the sending countries: they get rid of those who might press for reforms at the same time as the money that those emigres send home help prop up their governments. The LDS Church should be supporting people staying in their own countries and pressing for reforms; instead, they support the U.S. as a "pressure valve" for the corrupt elites of other countries.

D. Frankly, it isn't the U.S.'s fault that most illegal aliens come from Latin America, specifically Mexico. What we can do is make sure that illegal aliens are treated the same, no matter which country they're from. Programs like Secure Communities do just that, and once again, rest assured that an army of far-left lawyers will be standing at the ready in cases where local authorities engage in unlawful racially-oriented policies.

2. They also state:

As those on all sides of the immigration debate in the United States have noted, this issue is one that must ultimately be resolved by the federal government.

That's somewhat correct, but it needs to be noted that the federal government is supposed to represent the will of the people. The great majority of Americans oppose illegal immigration, but the federal government - whether under Barack Obama or George W Bush - continues to allow illegal immigration (and in some cases profit from it). They aren't acknowledging that the federal government is corrupt, nor are they acknowledging that states do have a major role to play in reducing illegal immigration (such as not giving benefits to illegal aliens), nor are they acknowledging the fact that some states are simply fed up with the feds allowing illegal immigration.

3. As if the above wasn't bad enough, they state:

The Church supports an approach where undocumented immigrants are allowed to square themselves with the law and continue to work without this necessarily leading to citizenship.

The fantasy that somehow millions of illegal aliens could be legalized and would not eventually be granted citizenship has been discussed here innumerable times; see for a start the entries on the guest workers page. See also comprehensive immigration reform for some of the downsides of any amnesty.

If you're a member of the Church of Jesus Christ of Latter-day Saints and you still think their ideas have merit, feel free to leave a comment and I'll try to change your mind.