Are citizens of Puerto Rico the US?

Yes, citizens of Puerto Rico are US citizens. Puerto Ricans have been US citizens since 1917, when the Jones-Shafroth Act was passed. This act granted US citizenship to all Puerto Ricans born after April 11, 1899. Puerto Ricans can vote in US presidential primaries, and they have a non-voting representative in the US House of Representatives. However, Puerto Ricans do not have the right to vote in the US presidential election, and they do not have a voting senator in the US Senate.