DES MOINES, Iowa (AP) — Iowa primary voters are set to pick potential replacements for two prominent members of the state’s U.S. House delegation. One is Republican who is retiring, the other a Democrat who is running for Senate. Democrats are choosing from among five candidates in the 1st Congressional District, a northeastern Iowa seat that is open after Democratic Rep. Bruce Braley opted to run for U.S. Senate.

Republican voters are picking from six candidates in the 3rd Congressional District, a Des Moines-area seat they are trying to protect after the announced retirement of popular 10-term Rep. Tom Latham. The stakes are high because Iowa’s four congressional seats are equally divided among the two parties and rarely see two vacancies in the same year.