一小撮 is a quantity phrase meaning 'a small pinch' (literally a tiny amount you can pick up with your fingers, used for powders or grains). In modern Chinese, it has a strong derogatory metaphorical sense — 'a handful (of bad people, reactionaries, criminals)', commonly used in political or social commentary to dismiss a small group as undesirable. The literal use is neutral, but the figurative use carries clear negative judgment. As a measure phrase, it is always preceded by a number (usually 一) and followed by a noun.