DES MOINES, Iowa (AP) — Republican Mitt Romney is visiting Iowa for U.S. Senate candidate Joni Ernst as her battle with Democrat Bruce Braley enters its final three weeks. The 2012 Republican presidential nominee is to headline an event Sunday evening in West Des Moines with Ernst, a state senator running against the congressman for the seat held by retiring Democrat Tom Harkin.

A Des Moines Register/Bloomberg Politics Iowa Poll published Saturday showed the race a dead heat, with Ernst holding a 48 to 47 percent lead over Braley, marking improvements by both candidates though more by Braley.

Romney’s visit, which also includes a stop in Cedar Rapids Monday, comes on the heels of Braley and Ernst’s second debate Saturday. Their final debate is set for Thursday in Sioux City.