The judge wrote that the editorials and column were opinions "based on disclosed and undisputed public facts" and "are not capable of the defamatory implications or innuendos" that Dougherty's lawsuit maintains.
Rau said that Dougherty also failed to show that the facts on which the opinions were based were false.
Joseph R. Podraza Jr., the lawyer for Dougherty, said he "respectfully disagreed with the trial court's ruling."
On Tuesday, Podraza said he would ask Rau to reconsider dismissing the lawsuit.
"If our motion for reconsideration is unsuccessful, we have every intention of seeking appellate review," Podraza added.
A spokesman for Dougherty, Frank Keel, noted that Dougherty had other pending lawsuits against the newspaper. Keel, in a statement Tuesday, said The Inquirer had "demonstrated a clear pattern of bias" against Dougherty.
In 2008, Dougherty, the head of Local 98 of the International Union of Electrical Workers, sought the Democratic nomination for the Philadelphia state Senate seat being vacated by Vincent J. Fumo, then under federal indictment.
The Inquirer opposed Dougherty's candidacy based on published articles about a federal investigation of the powerful union leader that came to light in 2006 when federal agents searched Dougherty's South Philadelphia home.
No charges were filed against Dougherty.