By Andrew Lapin The U.S. Supreme Court ruled that heirs to a German Jewish art dealer could use the U.S. court system to reclaim a valuable painting their family had used as a bargaining chip with the Nazis, even though the painting is currently owned by Spain. In a unanimous ruling Thursday , the justices found that the property-law dispute could be debated in court in California, where the descendants of Lilly Cassirer live today. Justice Elena Kagan, the only Jewish member of the court since Justice Stephen Breyer’s recent retirement, wrote the opinion. “Our ruling is as simple as...