DES MOINES, Iowa (AP) — Two Democrats vying to be Iowa’s next U.S. senator are scheduled to debate Thursday, as each seeks to convince voters he’s better positioned to flip the Republican-held seat in a contest that has seen heavy outside spending and high-profile endorsements. State lawmakers Zach Wahls and Josh Turek are competing in a June 2 primary. It is one of a few remaining competitive Democratic Senate primaries this year, as the party looks to find the best approach to reclaim the U.S.