Was it the black bean soup that drew them? If not, maybe the carrot ginger soup. Or was it the chance to mingle with not one, not two, but three Democratic presidential hopefuls in one spot?

The Story County Democratic Party's annual soup supper drew an estimated 300 activists to the Collegiate United Methodist Church on Saturday. And in the best tradition of early-voting Iowa — its caucuses remain the opening round of the presidential primary battle — voters and reporters flooded the downtown Ames church to surround White House wannabes Julian Castro, Kamala Harris and John Hickenlooper.

As local Democrats hunted for room at long tables, Kathy Byrnes of Des Moines held a tray of food and asked Harris, a U.S. senator from California, "How are you going to deal with the proliferation of pipelines?" At one point Harris stopped by the bustling kitchen to thank those preparing the food — and look longingly at the desserts.

Not 10 feet away, Sarah Pearson of Milwaukee, Wisconsin, asked Castro, secretary of Housing and Urban Development in the Obama administration, if he would support decriminalizing sex work. Nearby, Chelsea Chism-Vargas of Des Moines leaned in for a selfie with Hickenlooper and asked the former governor of Colorado his position on abortion rights.

With two dozen or more potential Democratic candidates forecast to seek the nomination — so far only 10 or so have taken at least a first step toward a bid — the yearlong political invasion of Iowa is just beginning.