When the Big Ugly Bill was being ushered in, Collins cast a critical vote to advance the legislation. Vance was brought in to break the tie. When it came up for a vote, she voted against it, but at that point her vote didn't matter. It turns out that "she cast that [critical vote to advance] just one day after private equity billionaire Steve Schwarzman, the chair of the Blackstone Group and a man who will personally reap huge rewards from the bill, kicked in $2 million toward her reelection effort."
There are lots of articles about it. Here's one from Rolling Stone - SUSAN COLLINS RAKED IN WALL STREET CASH BEFORE ADVANCING TRUMP TAX BILL
CONTACT Susan Collins:
413 Dirksen Senate Office Building
Washington, DC 20510
(202) 224-2523