Just a pet peeve of mine: the Senate cannot impeach. Impeachment refers to the bringing of charges, not removal from office. The House of Representatives is the body that can impeach, by a 2/3 vote. The Senate conducts the trial and votes to remove the impeached officer. Presidents Johnson and Clinton were both impeached, although neither was removed from office.
Yes, Clause 5 of Section 2 of Article I says that the HoR has sole power of impeachement. All I know that regardless that the HoR impeached Clinton, he was still in Oval Office chuckling because of the popularly elected Senate. I guess that I do not understand the impeachement process.
Also, given that the allegations of Obama giving aid and comfort to the nation's enemies are true, I wish that somebody in DC would try to throw Section 3 of the 14th Amendment at him.