Devalue: assets have only theoretical value until they are sold. You can borrow against that theoretical value, but the more you borrow, the less equity you have. Separate from using it as collateral for a loan, the value of an asset can drop for a variety of reasons. Real Estate can fall to disrepair. Stocks can fall due to lowered expectations for the future. If you end up owing more than it’s worth, there’s little incentive not to allow the value to completely evaporate. You can also use the loss to offset capital gains elsewhere, but that’s not particularly relevant here.

Divest: means to sell off assets, with the indication that the sale is at a loss for quick sale. Rich people often engage in the sale of assets to friends, family, and associates who offer pennies on the dollar in exchange for favors. Hiding assets through divestitures is a common tactic for wealthy people who are about to owe a lot of money.

Engaging in both can be used to transfer funds from his personal holdings to his political campaign, which in turn is paying off his legal debts and can be returned to his own pockets after the election. So by increasing the warchest, he is more likely to win the election AND can make himself whole after it is over.