Two leading Democrats running for statewide office in Pennsylvania will not appear alongside President Joe Biden at a Friday tour of a Pittsburgh-area tech development hub.

Biden will visit Mill 19, a tech hub developed by Carnegie Mellon University on the grounds of a former steel mill, to promote the bipartisan Infrastructure Investment and Jobs Act and discuss manufacturing and supply chains. Joining him will be Democratic Rep. Conor Lamb, who is running to replace retiring Republican Sen. Pat Toomey.

Scientists and engineers working at Mill 19, located in Hazelwood, Pennsylvania, work primarily on robotics and artificial intelligence.

Friday’s visit will be Biden’s second to the Pittsburgh area as president. He first announced the infrastructure bill in the western Pennsylvania hub in a March 2021 speech.

However, Democratic Lt. Gov. John Fetterman and state Attorney General Josh Shapiro will not attend due to scheduling conflicts, the Associated Press reported. Fetterman is currently leading the Democratic Senate primary field, several polls have shown, while Shapiro will likely be the Democratic nominee for governor.

Fetterman and Shapiro are not the first candidates in tight races to avoid the low-polling Biden. Georgia gubernatorial candidate Stacey Abrams also cited a scheduling conflict when explaining why she would not appear at Biden’s Jan. 11 voting rights speech at the Atlanta University Center. During that speech, Biden called for Senate Democrats to eliminate the filibuster to pass a pair of election nationalization bills, and compared his political opponents to segregationists.

Nationally, Biden is consistently polling below 45% support, with one poll showing him as low as 36%. In Pennsylvania, however, a poll conducted in late October by Franklin & Marshall College found that 32% of registered Pennsylvania voters thought Biden was doing a “good” or “excellent” job, a twelve-point drop from his June support.

A Morning Call/Muhlenberg College poll conducted in December found that a key source of Biden’s declining approval rating was Pennsylvanians’ frustration with the ongoing COVID-19 pandemic. Forty percent of Pennsylvania adults approved of Biden’s handling of COVID-19 at the time that poll was taken, down from 55% in the spring.