A “drift” to the Left? How about a stampede.
In the long term, the lefty orders are self defeating. They are aging slowly out of existence. The traditional orders and convents are growing. In my Catholic-mail (a higher order of USPS spam) I get requests for funds from traditional, and contemplative, orders that are not financially able to take all the would-be new postulants. Women don’t seek to join Social Service Agencies when they can do the same thing working for the government at much higher pay.
Not the Political Left, surely. If anything, it's only been within the last generation that factions within the American Catholic Church have toyed with drifting to the Political Right.