No, they will not even try to impeach obama. They would need to have 2/3 of the congress and senate to get an impeachment. That will never happen. trying would only make him stronger and give him YET another pity party that would infuriate his loyal obots. They would work 10x harder to get him re-elected.
This is the beginning of them getting rid of Holder. Once that is done, Obama becomes VERY exposed. This is them squeezing him on every angle until he no longer wants to be in the WH and tosses the election.
Impeachment requires only a simple majority in the House.