Legislator liability is an idea whose time has come. The tripartite government acts within the Judicial branch to establish the guilt or innocence of us mere mortals, why not the Legislative Branch (actually, they already are - I just want much higher penalties)? The average murderer kills for the most tawdry of reasons and thinks not about the consequences. People who have massive power and personally control millions of dollars, like our Senators (save, one - Bernie Sanders is not a Millionaire) and the bureaucrats like John Yoo (executive branch liability, too!) have so much more to lose... that the ultimate penalty would actually deter them.
I've always been in favor of setting black letter law for white collar thieves - steal $1meg or more and we execute you. That would cut WAY BACK on their schemes because, once again - they have so much to lose and would actually be deterred.
Finally, there is historical precedent - the Roman Senate had a rule, a Senator could propose any law - only if the law did not pass his fellow Senators would kill him.