FORT LAUDERDALE, Fla. — Even if the presidential election hinges on a Florida recount like 20 years ago, hanging chads and butterfly ballots won’t be around to trip up voters and officials — changes to ballots, equipment and laws have made the Bush-Gore circus a relic never to be revisited, state elections officials believe. Though there are other scenarios that make elections officials nervous, the computer punch-card ballots that fueled 2000’s chaos are buried in history’s landfill.