I was incorrect in my description above. I have only been making images from my existing install for some time, had forgotten details until I set up another fresh one recently. Of course I did not compile from source, this is all python. I get the tarred source, and run the executable from that. As long as the MD5sum from Electrum-1.9.8.tar.gz matches the site, and you checksum the executable each time you run it, you are 100% assured you are not running a trojaned version.
I recently set up the Electrum LTC client on Tails as well. Great job, devs, thank you for your work.