WASHINGTON — The U.S. Supreme Court ruled 6-3 Thursday that it would not overturn Michigan’s decision to uphold the conviction of Ervine Davenport, a Kalamazoo-area man who argued he was inappropriately shackled during his trial for murder in 2008. Justice Neil Gorsuch wrote the opinion for the court’s conservative majority, which was joined by Chief Justice John Roberts and Justices Clarence Thomas, Samuel Alito, Brett Kavanaugh and Amy Coney Barrett. Liberal Justices Elena Kagan, Stephen Breyer and Sonia Sotomayor dissented. All of the justices in the majority were nominated by Republicans, …