The 1911 Triangle Shirtwaist Company fire in New York City had led to the passage of dozens of labor laws in the mid 1910s. According to Wikipedia's entry on Al Smith (who was the speaker of the New York State Assembly and a member of the New York State Factory Investigating Commission, which proposed the laws):
New laws mandated better building access and egress, fireproofing requirements, the availability of fire extinguishers, the installation of alarm systems and automatic sprinklers, better eating and toilet facilities for workers, and limited the number of hours that women and children could work. In the years from 1911 to 1913, sixty of the sixty-four new laws recommended by the Commission were legislated with the support of Governor William Sulzer.
Other sources say that there were 36 laws, but whatever the precise number, there was a lot of new regulation.
The stagnation in the Utica population began about six or seven years after Smith's State Assembly (and Robert Wagner's State Senate) passed the Progressive-era laws, and the decline in the Utica population began about 15 years after.
According to Wikipedia, "Utica's economy centered around the manufacture of furniture, heavy machinery, textiles, and lumber." All of these are subject to factory regulation, which in effect raises wages. Employers contemplate the cost of regulation in their relocation decisions.
As well, the 1913 founding of the Federal Reserve Bank, also in the Progressive period, led to increased availability of credit. Easy credit meant reduced costs of relocation. There may have been early relocations of plants away from the city of Utica into surrounding suburban areas and into the South.
The combination of easing credit and increasing workplace and other regulation--the policy mix of both parties, but especially the Democrats--has been deadly to American manufacturing.
Instead of thinking about underlying causes of Trump's popularity, the American media has fixated on ad hominem attacks and shrill rhetoric.
Wikipedia's entry on Utica says that suburbanization began occurring in earnest in Utica in the 1940s, but there may have been an earlier trend as credit became available. The suburbanization of the pre- and post-war eras anticipated the broader globalization that followed the easing of credit and further expansion of regulation before and after the abolition of the international gold standard in 1971.
The post-1971 world has been brutal for those who create value. Those who live off the state as commercial or investment bankers, government contractors, government employees, and welfare recipients have fared well.
Unlike Syracuse, Utica does not have a nationally ranked university. Hence, it has not as easily participated in the state-subsidized education industry. Unlike Albany, it isn't a seat of an ever-expanding state bureaucracy. Unlike New York, the city that has benefited most from expanding credit, it is not a seat of global finance and bailout funding.
Utica actually produced goods of value like furniture. It was not a center of financial or political power, which produce nothing. Such production has been punished in the credit-based economy, which supports a limited degree of innovation and instead favors low-risk investments such as plant relocations.