Reply #16: Sounds like a good argument.

[Jim__]

Article I Section 6:

(The Senators and Representatives shall receive a Compensation for their Services, to be ascertained by Law, and paid out of the Treasury of the United States.) (The preceding words in parentheses were modified by the 27th Amendment.) They shall in all Cases, except Treason, Felony and Breach of the Peace, be privileged from Arrest during their Attendance at the Session of their respective Houses, and in going to and returning from the same; and for any Speech or Debate in either House, they shall not be questioned in any other Place.

Here's what wikipedia has to say about "breach of the peace":

The first two are somewhat self-explanatory; it has been suggested that the third is deliberately somewhat vague. The doctrine thus established is called Congressional immunity; it arose out of the necessity to prevent a vengeful executive from arresting members of the legislative branch on a pretext to prevent them from taking actions that the executive might find to be displeasing. In recent years, this doctrine has been used to prevent members from being stopped and held for speeding on their way to sessions; this apparently is not a "breach of the peace", where as perhaps another misdemeanor such as "drunk and disorderly" might be construed to be such.