Noooooo, states like New York and California would not inherently get more attention than Middle America.

A political candidate would need to secure (presumably) 51% of their entire parties base - and no, all the Democrats do not live in L.A. or San Francisco.

This is not that advanced of a concept. The mayors race went from 9 candidates to two over night. When you blow that up to the nation we would have 16-20 candidates at the start and 2 to chew over over three or four months.

A national primary is healthy and more true to pure democracy than anything the current system has to offer. The only real disadvantage is that the nation will be flooded with former campaign workers all at once rather than over five or six months!