For example
Hillary Clinton
http://clinton4.nara.gov/WH/EOP/First_Lady/html/columns/hrc021799.html
Senator Patty Murray
http://murray.senate.gov/news.cfm?id=189431
President Bush
http://www.issues2000.org/George_W__Bush_Social_Security.htm
I got these off Google in just a few seconds. You can find thousands of similar statements by politicians. They are selling it to the voters as a promise. And they are running the government. And they've been doing it for 60 years. If they break their promise now, then someone is going to hang.