trials coming up on different fronts, yeah. robert costa, thank you so much. well, the economy is one of the main conversation topics i have the iowa caucuses, now just four days away but it is not the only one. cbs's ed o'keefe is in ames, iowa, where he heard what is top of mind in the hawkeye state. >> the borders need to be closed. >> reporter: here in iowa, a top issue of concern for republican voters is the future of immigration and border security. >> yeah, the border is a big issue. >> open border is not a good thing. >> reporter: candidates speak about it frequently. >> the border is a disaster, the worst border in history. >> reporter: and offer solutions. >> into their catch and release we are going to go to catch and deport. >> reporter: but some use terms that vilify our document immigrants. >> century jurisdiction spewed : nationwide, americans are increasingly concerned. nearly half say it is a crisis. the issue is a long-standing concern for republicans, but there is increased worry among democrats and independents.