The primary season is ending as it began, with the Republican establishment on one side in state after state, and tea party activists on another. The competition is particularly strong in Delaware and New Hampshire, where GOP senatorial nominations are the prize, and New York, where Republicans pick a challenger for an uphill fall campaign for governor. Rhode Island, Massachusetts, Wisconsin and Maryland also hold primaries Tuesday, along with the District of Columbia. Among incumbents, veteran Democratic Rep. Charles Rangel of New York and Washington Mayor Adrian Fenty face particularly stiff challenges -- one because of ethics charges in Congress,...