Had Grover Cleveland been reelected in 1888, would Cleveland have been successful in avoiding various economic downturns from 1889-1893 and gotten elected to a third term?

The answer to this question depends largely on how one interprets the causes of the Panic and the depression that followed. Cleveland himself, during his second term, blamed the economic crisis on the Sherman Silver Purchase Act, passed during the Harrison presidency in 1890 (between Cleveland's two terms). But this is a highly contested claim, and economic historians point to many other factors. These include overproduction in industry and agriculture, rising indebtedness among farmers, a vast gap between the very rich and others, and international events. In any case, Cleveland's attempt to rein in the economic collapse by repealing the Sherman Act actually had the effect of taking money out of circulation and worsening the effects of the credit crisis on ordinary people. So claiming that Cleveland would have been able to stop the Panic of 1893 is based mostly on his advocacy of sound money, which would not have addressed any of the other causes of the depression. Whether he would have received (or even sought) a third term, of course, is a matter of pure speculation. There was no precedent for doing so, and Franklin Roosevelt only sought a third term because of the global crisis brewing in 1940. If Cleveland's second term had forestalled the economic crisis in 1893, there would have been no basis for him to seek a second term.
https://eh.net/encyclopedia/the-depression-of-1893/

https://millercenter.org/president/cleveland/domestic-affairs