The US authorities are preparing us for the possibility that there will be a major terrorist incident prior to the presidential election, which could result in the election being postponed or cancelled.

See for instance this story in the Guardian. The statement by Tom Ridge is here.

See also:
http://globalresearch.ca/articles/TAR407B.html
http://www.globalresearch.ca/articles/CHO402A.html
http://www.serendipity.li/wot/tarpley/tarpley.htm

I mentioned this previously here.

We are already living through a nightmare: it is more than possible that very much worse is to come. Those people who understand what happened on September 11th 2001 will recognise any new outrage for what it is. Unfortunately that is too small a number: others will be willing to accept more war and restrictions on their freedom all too readily.