Final answer:
According to the U.S. Constitution, a soldier can be a candidate for or hold civil office as long as they have not engaged in any treasonous acts.
Step-by-step explanation:
According to the U.S. Constitution, a soldier can be a candidate for or hold civil office. However, there are certain conditions that need to be met. The Constitution states that no person who has previously engaged in insurrection or rebellion against the United States or given aid or comfort to the enemies thereof, shall hold any civil office under the United States or any state. This means that a soldier can hold civil office as long as they have not engaged in any treasonous acts.