Joseph Smith:

There is one thing more I wish to speak about, and that is political economy. It is our duty to concentrate all our influence to make popular that which is sound and good, and unpopular that which is unsound.

History of the Church, Vol. 5, p. 286.

John Taylor:

The Elders of Israel begin to understand that they have something to do with the world politically as well as religiously, that it is as much their duty to study correct political principles as well as religious.

Journal of Discourses 9:338. Knowledge and Power Etc.

Heber J. Grant:

Many of the Latter-day Saints have surrendered their independence they have surrendered their free thought, politically, and we have got to get back to where we are not surrendering the right. We must stay with the right and if we do so God will bless us.

Conference, Oct. 1941, p. 144.

Joseph F. Smith:

We want you to be one both in temporal, political and religious things, in fact, in everything you put your hands to in righteousness. We want you to be one, one as God and Christ are one, seeing eye to eye. Do not try to crush anybody, or build yourselves up at the expense of your neighbor. Do not do it it is a custom of the world, and it is a wrong principle.

Journal of Discourses, Vol. 25, p. 251.

Joseph F. Smith:

Now, those are the Lord’s words (See D&C 98:5-7). There has been a tendency among some Latter-day Saints, even when the Constitution is mentioned, to say, “There he goes talking politics.” I am not talking politics. I am quoting the words of the Lord. Certainly, it is not meet that we should bring politics into the Church of Jesus Christ of Latter-day Saints, but just as certainly, it is meet that every member of the Church of Jesus Christ of Latter-day Saints take the doctrine of Christ into his politics and that he evaluate every candidate and every platform under any and every political banner in the terms of the gospel of Jesus Christ. If there be anyone who would destroy or weaken the Constitution of the United States, oppose him to the limit of your constitutional rights! Obversely, we should support candidates and foster platforms of whatever parties who will protect the sacred Constitution of the United States* — that just document of government which was divinely inspired.

* Our vote should not be based on popularity, but on correct principles.
Conference Report, April 1946. Rely upon the Lord.

Ezra Taft Benson:

Every member of the priesthood should understand the divine plan* designed by the Lord to raise up the first free people in modern times.

Ezra Taft Benson:

Each priesthood holder should use his influence in the community to resist the erosion process which is taking place in our political and economic life. He should use the political party of his choice to express his evaluation of important issues. He should see that his party as working to preserve freedom, not destroy it. He should join responsible local groups interested in promoting freedom and free competitive enterprise, in studying political issues, appraising the voting records and proposed programs, and writing to members of Congress, promoting good men in public office and scrutinizing local, state, and federal agencies to see that the will of the people is being carried out. he should not wait for the Lord’s servants to give instruction in every detail once they have announced the direction in which the priesthood should go. Each member should exercise prayerful judgment and then act.

Conference Report, Oct. 1961, pp. 69-75. The American Heritage of Freedom – A Plan of God.