Would you tell me whether I am right with my interpretation of the expression in bold in the following sentence?
The list so settled is now a slate, unless some discontented magnate objects and threatens to withdraw. To do so is called “breaking the slate”.
break the slate = withdraw one’s candidature
Thank you for your efforts.
Hard to tell for sure. The excerpt makes mention of magnates, not candidates.
But there is sometimes a more serious difficulty to surmount. A party in a state or city may be divided into two or more factions. Success in the election will be possible only by uniting these factions upon the same nominees for office. Occasionally the factions may each make its list and then come together in the party convention to fight out their differences. But the more prudent course is for the chiefs of each faction to arrange matters in a private conference. Each comes wishing to get the most he can for his clansmen, but feels the need for a compromise. By a process of “dickering” (i.e., bargaining by way of barter), various offers and suggestions being made all round, a list is settled on which the high contracting parties agree. This is a deal, or trade, a treaty which terminates hostilities for the time, and brings about “harmony.” The list so settled is now a slate, unless some discontented magnate objects and threatens to withdraw. To do so is called “breaking the slate.” If such a “sorehead” persists, a schism may follow, with horrible disaster to the party; but usually a new slate is prepared and finally agreed upon. The accepted slate is now ready to be turned by the machine into a ticket, and nothing further remains but the comparatively easy process of getting the proper delegates chosen by packed primaries, and running the various parts of the ticket through the conventions to which the respective nominations belong. Internal dissension among the chiefs is the one great danger; the party must at all hazards be kept together, for the power of a united party is enormous. It has not only a large but a thoroughly trained and disciplined army in its officeholders and office-seekers; and it can concentrate its force upon any point where opposition is threatened to the regular party nominations.
Well, I am still mystified as to why the word ‘magnate’ is used, but otherwise your assumption about ‘break the slate’ is right.