This isn't unique to Republicans, click around on:
Find U.S. Congress Interest Groups | MapLight - Money and Politics
Campaign Contributions Received by U.S. Congress Legislators | MapLight - Money and Politics
and you will see D/R are about equal, they just support different interest groups..
and here is your guy Sanders by the way:
Bernie Sanders (I-VT) U.S. Senate | MapLight - Money and Politics
"Total Campaign Contributions Received by Bernie Sanders: $90,133,362"
I wonder if he ever votes in favor of the interest groups that support him...
