The most damaging attack in any campaign is the one you didn't see coming. So find it first — by running the opposition research on yourself.
Pull your own record, your business dealings, your social-media history, your old public statements. Hand it all to someone you trust and tell them to build the case against you. Every vulnerability they find is one you can get ahead of with a plan, a document, and an answer ready to go.
Campaigns aren't lost by having a past. They're lost by being surprised by it. Do the digging before your opponent does.