For just a few months shy of 50 years, The Miami Herald’s hulking, block-long headquarters has occupied — some critics say marred — a prime spot on Biscayne Bay, a muscular symbol in marble, concrete, glass and steel of the newspaper’s and its leaders’ once-outsized clout in local affairs.

But is that commanding presence, the distinct tropical-meets-Modernist architecture, and the institution’s role in shaping Miami’s history significant enough to save the building from the wrecking ball as the newspaper itself decamps for suburban Doral?

That’s the ticklish question that will confront the city’s historic preservation board on Monday, when it considers an application by a leading preservation group, Dade Heritage Trust, to have The Herald building declared historic.

The designation would bar its demolition by its new owners, the giant Malaysian casino operator Genting, which wants to build a massive gambling resort on the 10-acre site now occupied by the newspaper building and a series of parking lots. Although designation by itself does nothing to stop a casino on the site — it only requires that the building’s exterior be preserved — Genting is strenuously opposing the petition.

The designation effort is shaping up as a familiar clash between business interests who want the building gone and belittle its value, and architects, historians and preservationists trying to save pieces of the history of a city best known for tearing that history down. But that effort comes with a twist: The building in question is a very large, and not universally beloved, example of a mid-20th Century style of Miami architecture that until recently enjoyed little popular favor.

The debate comes within a larger context. Preservationists across the country have increasingly turned their attention to saving endangered Modernist buildings that many people have trouble conceiving of as historically or architecturally valuable. In Miami, that new focus has led to the succesful designation as historic of the Miami Marine Stadium, the Bacardi Building and the row of funky 1950s motels along Biscayne Boulevard, and on Miami Beach to the preservation and renovation of iconic hotels like the Fontainebleau and Eden Roc — all of them rebaptized as Miami Modern, or MiMo, architecture.

Now Genting’s purchase of The Herald building, to some an equally significant MiMo monument, is forcing an overdue reevaluation of its architectural merits and its place in Miami-Dade County history, the Dade Heritage Trust and its supporters say.

They argue few other buildings in Miami embody so much history: Not just as an architecturally distinct example of the style of the day, but also as a marker of the role of the free press and the newspaper’s particular influence in the civic life and history of Miami, as well as the city’s explosive development in the last half of the 20th century.

They also note the building served as a base for owners John S. and James L. Knight, who helped revolutionize the newspaper industry, in part through their commissioning of The Herald’s then-technologically advanced headquarters, as well as longtime executive Alvah Chapman, one of the city’s key civic leaders for more than three decades. Chapman helped create the county’s extensive homeless-assistance system and guided the rebuilding of South Miami-Dade after Hurricane Andrew in 1992. Chapman’s widow, Betty, is supporting designation.