Another word for “government by consent” is:

Locke is thus also important for his defense of the right of revolution. ... property rights with respect to one another on the basis of owning their labor. ... in the right sense of the word for the workmanship model to be correct. consent of the governed. A condition urged by many as a requirement for legitimate government: that the authority of a government should depend on the consent of the people, as expressed by votes in elections. (See Declaration of Independence, democracy, and John Locke.)

Explanation:

an earnest tone.

because portia wants to know why brutus has been acting strange lately.