It is ‘pro temp’, not pro tem, Latin for pro tempore
Good work with the Biden hack.
From: http://wiki.answers.com/Q/Who_is_the_president_Pro-Tem_in_the_senate
Who is the president Pro-Tem in the senate?
In: US Presidents
Answer
Robert Byrd (D) West Virginia
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Perhaps we have a case of you say pro temp and I say pro tem. We both mean the same deal.