Macri denounces "treason" while all eyes focus on Peronist economic team's announcement
Peronism will hold a majority in the Senate, but will need regional or opposition allies to pass laws in the lower chamber.
President-elect looks to strike the right notes in foreign policy and with allies at home
Peronism could reach a majority in both chambers by negotiating with a few minority parties
Ruling coalition expected to move from 25 to 31 seats, putting it close to controlling the chamber in case of re-election