The text of this great contract is worthy of study. No stronger or more comprehensive words could be employed, whether we regard the object, the party guarantying, or the party guarantied. The express object is “a republican form of government.” This is plain. The party guarantying is not merely the Executive or some specified branch of the National Government, but “the United States,” or, in other words, the Nation. The Republic, which is the impersonation of all, guaranties “a republican form of government”; and every branch of the National Government must sustain the guaranty, including especially Congress, where is the collected will of the people. The obligation is not less broad, when we consider the party guarantied. Here there can be no evasion. The guaranty is not merely for the advantage of individual States, but for the common defence and the general welfare. It is a guaranty to each in the interest of all, and therefore a guaranty to all. And such is the solidarity of States in the Union, that the good of all is involved in the good of each. For each and all, then, this guaranty must be performed, when the _casus fœderis_ arrives. As guarantor, the Republic, according to a familiar principle, is to act on default of the party guarantied; and then the duty is fixed in all its amplitude. The testimony is complete. This clause was no hasty or accidental amendment, creeping into the Constitution by stealth or compromise, obscure in language and open to various interpretation, but a solemn act, couched in few, lucid, unmistakable words; and its precise purpose was just what so plainly appears,--to keep all the States truly “republican,” and make the whole numerous people, in the development of the future, homogeneous and one. By these words the Nation is not only empowered, but commanded, to perform the great guaranty. Power and duty here concur. Mr. Webster was right, when he called this provision “a very stringent article, drawing after it the most important consequences, and all of them good consequences.”[58]