Former Vice President Joe Biden will travel to Pennsylvania’s 18th district to support Democratic U.S. House candidate Conor Lamb ahead of a March 13 special election, an aide to Biden confirmed Thursday to The Daily Beast. During an address to House Democrats on Wednesday, Biden gave Lamb, a Marine veteran and former prosecutor, a shout-out saying he has a “genuine chance of winning” the seat. “Mr. Vice President, they called you PA’s third Senator for a reason: You know our people. Thanks for the support,” Lamb responded on Twitter. The race, taking place in a district President Trump won by nearly 20 points, will be a true test of potential Democratic strength ahead of the 2018 midterms. It is also the beginning of a reportedly aggressive campaign Biden will mount for a number of Democratic incumbents this year. Biden’s American Possibilities PAC also sent out a fundraising email on Lamb’s behalf Thursday. The exact date and details of the visit are still being determined, the aide said. —Gideon Resnick