Further, if there is such a rule and he did that, why wasn't there an investigation by the House ethics committee?
Who controls committee investigations? answer the Reps.
The Reps didn't want to kill their chances in 2000.
It was bad enough that the Reps felt they had to bar Lazio from making a speech at the Rep Convention, which probably cost Bush 2,000,000 votes and 4 seats in the Senate.