What are the powers of the congress which three do you think is most important?

the constitution gives congress the power to regulate commerce "among" the several states.

Nativism is the political policy of promoting or protecting the interests of native or indigenous inhabitants over those of immigrants,[1] including the support of immigration-restriction measures.[2]

In scholarly studies, nativism is a standard technical term, although those who hold this political view do not typically accept the label. Oezguer Dindar wrote, "[N]ativists [...] do not consider themselves [to be] nativists. For them it is a negative term and they rather consider themselves as 'Patriots'.[3]