I've gotten a large portion of this data from
http://www.law.cornell.edu/background/impeach/impeach.htm1. The House Judiciary Committee deliberates over whether to initiate an impeachment inquiry.
2. The Judiciary Committee adopts a resolution seeking authority from the entire House of Representatives to conduct an inquiry. Before voting, the House debates and considers the resolution. Approval requires a majority vote.
At present, the political composition of the House is 232 Republicans, 202 Democrats, and 1 independent.
In order for the House Judiciary Committee to begin an impeachment inquiry, at least 218 aye votes must be cast. If every Democrat and Bernie Sanders voted "aye," 15 Republican votes would still be needed.
3. The Judiciary Committee conducts an impeachment inquiry, possibly through public hearings. At the conclusion of the inquiry, articles of impeachment are prepared. They must be approved by a majority of the Committee.
At present, the political composition of the House Judiciary Committee is 21 Republicans and 16 Democrats.
In order for articles of impeachment to be approved by the Committee, at least 19 "aye" votes must be cast. If every Democrat voted "aye," 3 Republican votes would still be needed.
4. The House of Representatives considers and debates the articles of impeachment. A majority vote of the entire House is required to pass each article. Once an article is approved, the President is, technically speaking, "impeached" -- that is subject to trial in the Senate.
In order for those articles of impeachment to be passed, at least 218 aye votes must be cast. If every Democrat and Bernie Sanders voted "aye," 15 Republican votes would still be needed.
5. The Senate holds trial on the articles of impeachment approved by the House. The Senate sits as a jury while the Chief Justice of the Supreme Court presides over the trial.
6. At the conclusion of the trial, the Senate votes on whether to remove the President from office. A two-thirds vote by the Members present in the Senate is required for removal.
The present composition of the US Senate is 55 Republicans, 44 Democrats, and 1 independent.
In order to remove a President from office, 67 votes are necessary in the Senate. If every Democrat and Jim Jeffords voted "aye," 22 Republican votes would still be needed.
7. If the President is removed, the Vice-President assumes the Presidency under the chain of succession established by Amendment XXV.