BOSTON (AP) — Top U.S. election security officials say current threats to the nation’s voting systems are more complex than ever. The task of protecting those systems has become increasingly more difficult as next week’s midterms loom. That’s partly because millions of Americans embrace unfounded conspiracy theories about supposed election-rigging. Election officials are girding for harassment, intimidation and even physical violence at polling places and elections offices during and after voting, as ballots are counted and results certified. Making matters worse, global rivals are expected to deepen disinformation efforts. Experts say a disruptive cyberattack also is possible. Russia, Iran and China may have fewer qualms these days about destabilization-inducing aggression.