Delaney, a Montgomery County native, came out as the surprise winner in the primary elections.
Congressmen Bartlett has been leading the sixth district for two decades, serving as a member of the Republican Party and the Tea Party Caucus.
He credited Delaney's win to the redrawn 6th District, that now includes a large portion of Montgomery County.
Bartlett said getting another term in office proved to be more challenging this time. The district lines now go into the much more liberal parts of Montgomery County, after redistricting.