
All 149 of them could be allowed to vote; or only about 99 of them if 50 are disqualified from voting because they are themselves among the 308 targeted lawmakers.
If the entire 149-member Senate is allowed to cast votes, three-fifths of the votes (about 90) are required for impeachment. In the latter case, with around 99 remaining, the three-fifths ratio means 60 votes would be required.
There are now 56 senators potentially hostile to the Yingluck government, including the anti-government Group of 40 Senators and some swing voters.
The votes of these 56 would not be sufficient to impeach the 308 in the case of the entire 149-strong chamber voting.
There has never been an impeachment case that has won more than 90 votes in this six-year-old Senate.
In the latter case, impeachment is a possibility, as only five more votes are needed, given that all of the 56 senators approve of impeachment.