There’s something different about the crop of Democrats running for Congress in 2018. As in previous years, the party has recruited a small army of veterans in high-profile races and in Republican-held districts. There are loads of state legislators, business owners, and government officials. But the candidates also include a volcanologist who’s worried that her favorite research spot will be opened up for development; an aerospace engineer who’s running against the climate-denying head of the House Science Committee; a pediatrician who spends part of the year treating leprosy patients in Vietnam; and a physicist who worries what budget cuts would mean to the federal research facility where she spent her career. All told, more than a dozen Democratic candidates with science backgrounds have announced their candidacies for Congress or are expected to in the coming months.