Explain the meaning and nature of de-facto and de-jure governance regimes.Use case law and constitutional doctrine, where appropriate

De facto and de jure are Latin phrases that mean "in fact" and "in law," respectively. They are used to differentiate what happens in practice from what is supposed to happen according to law.

De facto governance refers to a situation where power is held and exercised by a body or individual that is not legally recognized. This could be due to a power vacuum, where the legitimate government is unable to exercise its authority, or it could be a situation where power has been seized unlawfully. Despite the lack of legal recognition, a de facto regime has power in practice because it controls the machinery of government.

On the other hand, de jure governance refers to a situation where power is held by a body or individual that is legally recognized. This is the normal situation in most countries, where the government is recognized by the constitution and laws of the country, and its authority is accepted by the people and other nations.

Case law and constitutional doctrine provide numerous examples of these concepts. For instance, the Supreme Court of the United States in the case of "Nixon v. United States" (1993) dealt with a de jure situation. The Court held that the Senate had the de jure power to decide how to try an impeachment, and its decision could not be reviewed by the courts.

A historical example of a de facto regime would be the government of Southern Rhodesia (now Zimbabwe) from 1965 to 1979. After unilaterally declaring independence from the United Kingdom, the regime was not recognized by the international community but continued to exercise power within the country.

In conclusion, de facto and de jure governance regimes refer to the practical and legal realities of power, respectively. They are important concepts in understanding the complexities of political power and authority.