re: Lying?
"ExxonMobil contributed $252,500"
This is a little short of $1,600,000.
But even if ExxonMobil gave 50 million to AEI, it doesn't make AEI a lobby group.
And according to their website:
"AEI's operations are financed by donations from corporations, foundations, and individuals and by investment earnings from an internal endowment. "
http://www.aei.org/about/filter.all/default.asp
So, the bit about "AEI, unlike some think tanks, has no endowment" doesn't appear to be accurate.
But if the Guardian had used "think tank" instead of "lobby group", then their article would been less misleading.