As it is the only Union party, so the Republican party is the only Constitutional party. It is the only party which takes the Constitution unreservedly as guide, according to the spirit in which it was made, and the light of its Preamble,--rejecting the Proslavery interpretations adopted by the Bell faction, the Breckinridge faction, and the Douglas faction, all of which, in whatever form, are abhorrent to the spirit of the Constitution and the very words of its Preamble. In that Preamble it is declared that the Constitution is made to “establish justice, insure domestic tranquillity, provide for the common defence, promote the general welfare, and secure the blessings of Liberty to ourselves and our posterity.” Mark these important words. It is to establish justice: but Slavery is injustice. It is to insure domestic tranquillity: but Slavery insures domestic discord and insurrection. It is to provide for the common defence: but Slavery causes common weakness. It is to promote the general welfare: but Slavery perils the general welfare. Finally, it is to secure the blessings of Liberty to ourselves and our posterity: but Slavery sacrifices these blessings. Such is the Preamble, which is the key to the Constitution. The Republican party alone adopts its principles, as it alone adopts most honestly and sincerely the often declared opinions of its founders. Therefore it is the only Constitutional party. For the Union and the Constitution, the Republican party is also the only party which maintains the great principles of Human Freedom. Thus in every respect is it commended to your support. The man who asks you here in Massachusetts to vote against it is either very weak, and believes in his own bad reasoning, or very artful, and laughs in his sleeve at your credulity, or very spiteful, and allows all things, even his principles and his country, to be lost in the gratification of a vindictive temper. Look at your opponents here, and you will find that weakness, duplicity, and spite are the three main springs to their conduct. This is a severe analysis, but I think the facts support the assertion.