For the 6-year term beginning in 2013:
Bob Casey Jr. (D-PA) - senior senator
For the 6-year term beginning 2017:
Pat Toomey (R-PA) - junior senator
*For updated information, see the related US Senate link below.
Specter and Casey.
No they are not.
Each State has 2 Senators
There is a list of all current US Senators at the related link below.
US Senators are chosen by state wide elections.
There are 2 US senators from Pennsylvania. And, they are Bob Casey,Jr. and Pat Toomey.
The US Senators from Pennsylvania are Casey and Specter.
Pennsylvania has two US Senators: Robert Casey and Arlen Specter.
There is a list of all current US Senators at the related link below.
Many folks get confused between the STATE Senate and U.S. Senate. In the U.S. Senate there are 2 senators from each state. For Pennsylvania these two senators represent the state's interests in the federal government. Within the the Pennsylvania state government there are 50 senators who represent their respective districts in Harrisburg.
Senators do not 'represent' a city; they represent the entire State (The Commonwealth of Pennsylvania).
As of October 2021, Pennsylvania's current US Senators are Pat Toomey and Bob Casey Jr. Pat Toomey has been in office since January 3, 2011, and Bob Casey Jr. has been in office since January 3, 2007.
Both are men. One is a Democrat, and the other is a Republican.