For instance, during his first presidential campaign, the media informed America that Bill Clinton was a moderate Democrat. Even after the Clinton administration tried to socialize the whole of the American medical delivery system, the media still referred to him as a moderate, rather than the socialist he is. The reply was but a blank stare. Perpetual propaganda from a meddlesome media. They are extreme left to the max.
Control freaks, too.
So we see, moderate and centrist are synonyms and can be used interchangeably. Those on the left of the political spectrum, all of the Democrats and many Republicans, tend to support big government controlled socialism. That is, they sponsor programs to redistribute the wealth, legislate equality even when it is physically impossible, attempt to regulate everything in life through federal law and regulations, and attempt to control the population through a quagmire of very restrictive taxes, social programs and mandates. Those on the right tend to believe that government should control the morality of the nation and that strict laws are necessary to make people behave as ordered. There are position overlaps between the far right and far left, of course.