BATON ROUGE, La. (AP) — Republican Rep. Bill Cassidy is returning to Washington, to begin preparations for his transition to the Senate, after a decisive weekend victory over Democratic incumbent Mary Landrieu.

In addition to the many orientation tasks, Cassidy has a meeting Tuesday with incoming Senate Majority Leader Mitch McConnell, where he expects talk of committee assignments will come up.

He already knows he's gaining a position on the energy committee. That's a promise McConnell made to Cassidy to help undercut Landrieu's touting of her committee position as essential to energy-rich Louisiana.

Cassidy posted a 12-point victory in Saturday's runoff over Landrieu, Louisiana's last statewide Democratic elected official. With her defeat, Democrats no longer hold a Senate seat in the Deep South and the GOP's Senate majority in January was extended to 54 seats.