There are only three papers in PA, the Philadelphia Inquirer (688,670), the Pittsburgh Post-Gazette (341,474) and the Harrisburg Patriot-News (93,000).
While the Allentown Morning Call (117,977) and the Tribune Review (149,068) have larger Circulation then the lowly Patriot-News, the Patriot News is the dominate newspaper in the Middle of the state, the Post-Gazette is the Dominate Newspaper in the Western Part of the State (and that includes much of the Mountains where it is often purchased with whatever local paper is purchased in the area, the local dominate gas station carries it in Altoona and points East). The Inquirer is by far the largest Newspaper but that is more a reflection of the size of the Philadelphia Metro-Area as compared to the Pittsburgh Metro-area. The Patriot-News is carried even in Johnstown, but in a store catering to the local Courthouse (Harrisburg is the State Capital so news from Harrisburg is often sought even in Johnstown).
As to the Morning-Call is strictly regional, i.e Allentown. The Tribune Review is a joke (i.e. As part of its owner's divorce case the status of the Tribune-Review came up, is it a variable business or is it a hobby? This came up in the Mellon-Scaife Divorce case, but was quickly sealed by the Court but the Post-Gazette did report it). Most other newspapers are very regional, i.e. very rarely seen outside the county they are produced in.
For list of Newspaper circulation see:
http://abcas3.accessabc.com/ecirc/newsform.aspJust pointing out that this endorsement is NOT from a Major Paper in the state, just a regional one and one has to give it the weight one gives to any regional paper.