Other forms: reformists
In politics, someone who believes that a government or economy should be improved through gradual changes is a reformist.
Reformists tend to focus on working within existing systems and pushing through small changes over time, even if they believe those systems need major repair and reform. In politics, they are often compared with revolutionaries, who advocate for completely overhauling broken governments or societies and replacing them with something new. The Latin root of reformist is reformare, "to form again."