With the Republican National Convention only two months away, the city of St. Paul and local business leaders are scrambling to fill all of those empty downtown storefronts. The city has a downtown building vacancy rate of more than 20 percent, so they're trying to lure merchants from other parts of the city to set up temporary shops along the skyways and ground level storefronts, at least for the week of the convention. The move is partly intended to make the city's core look more alive when the national spotlight shines on St. Paul the first week of September.