KALAMAZOO, MI (WHTC) - A possible Democratic challenger for the US House seat currently held by Republican Fred Upton has pulled out of the race. Family members say that John Waltz of Kalamazoo had to end his campaign after suffering a stroke and multiple seizures over the weekend. Party officials say that the search for more candidates is ongoing. Upton is facing a GOP primary challenge in August from Jack Hoogendyk. All Allegan County residents outside of the City of Holland will be choosing their Congressional representative from this 6th District after reapportionment due to the 2010 census moved them out of the 2nd District, currently represented in Washington by Bill Huizenga.