Communism is mostly linked to repression because of the Soviet Union. The connection can be seen because it is against human nature to want to share all earning absolutely equally, so in order to get people to do this the government must step in and repress.
An example of power that the United states Constitution delegates to the national government is that it can declare war. States can conduct elections, enforce laws and borrow money.
The answer is non-sampling errors.
Non-sampling errors refer to any type of error/mistakes in data collection process that does not involve to the sample selection itself, which cause the data not truly representing the value in sample population.
Other example of a non-sampling error is when there is a member of research team that purposely changing the data.
