URBANDALE — Ambitious Republicans are starting to make moves in Iowa, long a proving ground for future presidents. Their first step is finding out whether activists here have gotten over the last one.Former Secretary of State Mike Pompeo was the first to confront that obstacle, portraying himself Friday to Iowa GOP activists as a loyal champion of former President Donald Trump’s agenda but in his own brand of plain-spoken, Midwestern conservatism.Trump remains a hulking presence in Iowa, where he won twice by healthy margins.