The Book of Mormon is an abridged version of historical events and religious teachings that occurred over hundreds of years here in the Americas. It is another testament of Jesus Christ.
Most of the material in the Book of Mormon occurred while the inhabitants functioned under a democracy; although all forms of government were present, including monarchies, theocracies and tribal governments. It was a democracy, but perhaps not our modern definition of democracy. It was as democratic as you can be when judgeships are passed from father to son.
Guidance on government is scattered throughout The Book of Mormon, but is concentrated in Mosiah 29. Below are some relevant passages:
26 Now it is not common that the voice of the people desireth anything contrary to that which is right; but it is common for the lesser part of the people to desire that which is not right; therefore this shall ye observe and make it your law—to do your business by the voice of the people. 27 And if the time comes that the voice of the people doth choose iniquity, then is the time that the judgments of God will come upon you; yea, then is the time he will visit you with great destruction even as he has hitherto visited this land.
32 And now I desire that this inequality should be no more in this land, especially among this my people; but I desire that this land be a land of liberty, and every man may enjoy his rights and privileges alike, so long as the Lord sees fit that we may live and inherit the land, yea, even as long as any of our posterity remains upon the face of the land.
Clearly, The Book of Mormon teaches that government should be conducted by majority rule and that we should seek equality.
King Mosiah’s father, King Benjamin, also instructed the people in government and expressly affirmed that he supported himself, not at the people’s expense. See Mosiah 2:14:
And even I, myself, have labored with mine own hands that I might serve you, and that ye should not be laden with taxes, and that there should nothing come upon you which was grievous to be borne—and of all these things which I have spoken, ye yourselves are witnesses this day.
Several passages exist in The Book of Mormon where excessive taxation and governmental excesses are condemned. See especially Ether 10:5, Ether 10:6, Mosiah 11:6, Mosiah 7:15 and Mosiah 11:3.
Mormons do not like to see government overstep its boundaries. They prefer that it be limited and exist in a particular sphere.
Throughout The Book of Mormon defensive military efforts were judged as righteous, as long as people were defending their lives and their liberties and led by righteous leaders. See especially Captain Moroni.
Mormons tend to support a strong military. Currently, this is more in line with the Republican party than the Democratic party.
The Book of Mormon clearly teaches that government has a responsibility to protect religious freedoms. Mormons tend to view the Republican party as supportive of religion and the Democratic party as being non-supportive.
Unrighteous judges and lawyers are portrayed in The Book of Mormon as detrimental to society. See Alma 10:27:
And now behold, I say unto you, that the foundation of the destruction of this people is beginning to be laid by the unrighteousness of your lawyers and your judges.
Most lawyers in the United States are Democrats. I know this from all my schooling, training and experience. Most lawyers contribute money to Democratic candidates and always have.
Mormons tend to associate corrupt lawyers and Judges with the Democratic party.