MIAMI — A majority of Cuban Americans in Miami Dade disapprove of President Joe Biden’s handling of key issues like the economy and Cuba policy and intend to overwhelmingly support Republican candidates in the midterm elections, according to a poll by Florida International University released Tuesday. Just 30% of Cuban Americans living in the county support Biden, compared to the 42% who on average backed the president in national polls conducted in September. A strong majority (64%) of respondents to the FIU Cuba poll, a telephone survey of political attitudes in the Cuban American community …