Very perceptive of Bee, the same idea went through my mind too!
There's a clear difference between the chances of a divorce and actively pursuing one. ChllaB's post is concerned with the former and much of the discussion surrounds that.
However for an election chart, the situation is totally different. Divorce is a legal process, and you need an election chart which maximises your chance of 'winning' the outcome. The issue of Astrological significators of divorce is moot, as you have already decided on that. The issue is the relative strength of you (ruler of the Ascendant in the election chart) and Him (ruler of the seventh in the election chart - not because he is your partner but because he is your opponent) and the relationship to the legal process - in this case the tenth, which signifies Judges and legal outcomes. Preferably your significator (the Ascendant ruler) should be full of essential AND accidental dignity and be well positioned in respect of the ruler of the tenth (the Judge and legal process).
Essential dignities would be rulership, exaltation, triplicity in that order
Accidental dignities show the ability to exercise that strength, and would include angularity. swift in motion, direct, in favourable aspect with Venus and/or Jupiter (assuming that they are not debilitated) and free from aspects from the malefics.
Lord 7 should preferably have all the opposite qualities, being essentially and accidentally debilitated and in a poor aspect or no aspect to the Judge/legal process.
However, there are always practical limitations to acheving such things. For example the favourable chart might be for 4 am or on a Sunday, both of which prevent immediate commencement of legal proceedings. In practice you are looking for a situation where your significator is as strong as possible (possible being times that can be used to initiate action) compared to his significator.
You also need to look at the lawyer's strength too. Your lawyer is Lord 2 his lawyer is lord 8. If you can't debilitate him, try debilitating his lawyer, and giving yours dignity. Finally the decision is fourth House and you want a Lord 4 in a good aspect to your significator. Decision here is not so much the outcome, which will of course be divorce but the settlement and how favourable it is to you as opposed to him.
This is worth considering for any legal proceedings, short of divorce, which apportion possessions or custody of children, just as much as for divorce proper.
As a comment on the previous discussions about Astrological signification of divorce, I'd simply add that marriage is a two way process, and we really should consider both parties, plus the interaction of the two natal charts, any directions, progressions/profections, solar returns etc. You also have to place a lot of emphasis on the social mores - is divorce something which is socially acceptable, easy or dificult to obtain, easy or difficult for wives rather than husbands, etc. In some societies divorce is not acceptable, or is easier for men rather than women. What we will have is a situation of people living together, though not liking the arrangement. Some couples may stay together for the sake of children, or separate but not undertake any legal proceedings at all - i.e. live separate lives, but not be legally separated.
ChllaB puts forward a good list of possible indicators of second marriages, though a first marriage here does not have to end in divorce - one partner may die and the other eventually remarry.
You can't really look at a natal chart on it's own and conclude there will be a divorce. What you might identify is that the person may have difficulty with relationships.
Saturn is opposing my all too, except from the Moon, Sun and Pluto. He is my chart ruler, I'm Capricorn rising. And he's been going forward and backward in my 8th house which can also relate to the matter.