Why was the pension issue relevant to the politics of Cleveland's presidency?

Due to high tariffs, pensions became a way to use the exceedingly high Treasury surplus.

President Grover Cleveland was the only US President to serve in two non-consecutive terms (From 1885 to 1889 and from 1893 to 1897). During his presidency, he vetoed a bill who proposed granting pensions to Civil War Union veterans, as well as the Dependent Pension Bill who would grant a pension to anyone serving in the military for more than 90 days. He argued that many claims would be fraudulent.

President Cleveland assumed office during a critical time for the country, as it was passing through a severe economic depression. These decisions of vetoing pensions followed his policy of austerity.