ROCKLAND, Me. — Reade Brower cuts an unassuming figure for a media mogul.

On a drizzly October day here, he could be found tucking into a grilled cheese sandwich with bacon at the Home Kitchen Café, clad in a Hawaiian shirt, shorts and a Red Sox cap. He was wearing shoes, which he often forgoes, as he had when he ran a recent marathon.

Appearances aside, however, Mr. Brower’s footprint on this state’s newspaper industry is enormous.

He owns 18 weeklies and four of the seven daily newspapers in Maine, and his presses print the other three. In 2016, Mr. Brower, 61, and a partner bought two Vermont dailies. His latest acquisition came this year, when he bought The Lewiston Sun Journal, Maine’s second-largest daily, along with its presses, and more than a dozen weeklies.

Mr. Brower’s hold on the newspaper industry of a single state stands out, even in an age of increased consolidation that has led to hand-wringing over the influence of giant technology companies and wealthy media owners like Rupert Murdoch, Jeff Bezos and Sheldon Adelson. Maine’s emergence as a national political hot spot — whether for Gov. Paul LePage’s combative conservatism or Senator Susan Collins’s pivotal position as a centrist Republican — adds to the influence Mr. Brower could have over the public discourse through his properties.

Mr. Brower seems to greet it all with a shrug.

“I don’t feel at all powerful,” Mr. Brower said. “My job is to create a sustainable business model that keeps people who want to be working in this industry working. And to have enough money coming in to pay the bills and make a profit so it’s a viable business. I don’t feel this surging power. All of the papers continue to operate autonomously.”