What does the first or the second refer to here?

Context:

However, the state's suspension of the prewar government did require the United States to put down the rebellion and reestablish the proper relationship between Texas and the federal government. These obligations were created by the Constitution in its grant of the power to suppress insurrections and the responsibility to insure for every state a republican form of government.[16] From the decision:

“ The authority for the performance of the first had been found in the power to suppress insurrection and carry on war; for the performance of the second, authority was derived from the obligation of the United States to guarantee to every State in the Union a republican form of government. The latter, indeed, in the case of a rebellion which involves the government of a State and for the time excludes the National authority from its limits, seems to be a necessary complement to the former.[