The Democratic State Convention of Alabama, which assembled a few days ago at Montgomery, has initiated a course of action which, if imitated by other Southern commonwealths, will most probably result in a disastrous political rupture, and may possibly precipitate a dissolution of the Union. The full account of the proceedings has not come to hand, but we learn by telegraph that the Convention adopted by a large majority a series of resolutions insisting upon the principle that it is the duty of Congress to protect slavery in the Territories, and requiring the Alabama delegation to Charleston to insist upon the endorsement of the platform by the National Democratic Convention before nominating a candidate for the Presidency, and in case the Convention fail to do so, they are instructed to withdraw and take no further part in the proceedings. In other words, the Democracy of Alabama have resolved that the National Democratic Convention shall affirm their particular and ultra Southern view of the slavery question, and it is only upon that express condition that they will consent to remain in the Convention, and participate in the selection of a Presidential candidate.

It must be acknowledged that Alabama has assumed a bold—we may say, a dangerous position. She undertakes in advance to dictate a platform to a convention of delegates representing the entire Democratic party. Instead of leaving the subject to the body specially invested with authority to frame a programme of principles which will command the approbation of the party in every quarter of the Union, she virtually places before the Convention the alternative of accepting her particular views, or of witnessing her secession from that assemblage. The course pursued by Alabama denotes a foregone conclusion, and indicates clearly enough, as far as she is concerned, a rooted distrust of the Democracy of the free States, and a settled determination to enforce upon them her extreme doctrines, or failing therein, to strike the first blow towards the denationalization of the only party which can be relied upon as antagonistical to Black Republicanism. The wisdom and expediency of this decision may well be questioned.

Heretofore, Alabama, while invincibly Democratic, and strongly Southern rights, had never sanctioned any policy tending even remotely to the dissolution of the Union. Her resolves at the late Convention prove how profoundly agitated the public mind of the State must have been by recent developments of abolition insanity, and how completely shaken must be the confidence hitherto felt by her leading men in the integrity and soundness of the Southern Democracy. At a single leap Alabama has almost placed herself side by side with South Carolina. It is doubtful whether the latter State will so far recognize the Charleston Convention as to elect delegates to that body; but should she do so, we may feel altogether certain that they will be instructed to pursue a line of action at least as trenchant and decisive as that traced by Alabama. The example set by the latter will probably be followed by Georgia and Mississippi, and may meet the sanction of all the cotton-growing States. Now it is palpable that if any considerable number of Southern States go before the Charleston Convention with the unflinching resolve to compel the formal recognition and endorsement of the theory of federal protection of slavery and a Congressional slave code for the Territories—tenets which the Democracy of the North will never sanction—there is a complete end to all prospect of harmony. A national Democratic nomination will be rendered impracticable. The refusal of the majority of the Convention to adopt the Alabama platform will be the signal for the withdrawal of most of the Southern delegations. The remaining members of the Convention may nominate candidates, but they will be to all intents and purposes sectional nominations. The South, in its turn, will select its champions, and then we shall have precisely that condition of things which the Charleston Mercury long since counseled and advocated—viz.: a sectional Democracy confined to the South, while everywhere else parties will be considered as more or less tainted with Abolitionism.

We need scarcely say that so lamentable a result would prove absolutely ruinous, not simply to the fortunes of the Democracy, for that would be of comparatively little consequence, but to the hopes of those national, conservative citizens, who cling to the Union and its preservation as the means of consolidating our liberties, our prosperity and our strength. If the Democratic party break to pieces, we can discover no bulwark to the encroachments of fanaticism, and therefore no safety to the South. The Union cannot possibly survive sectionalism in every part of the republic.