In total, there are 84 current members of the House and Senate who cast ballots on either Clinton’s impeachment or on his possible removal in the Senate. Most of those veterans of the Clinton impeachment are Democrats, and, therefore, most opposed the articles of impeachment or removal.
There are 41 sitting Democratic members of the House who voted against all four articles targeting Clinton. Another six Democrats who are now senators then served in the House, where they voted against all four articles. One current House Republican, Rep. Peter T. King (N.Y.), voted against the four articles as well. Republicans were more likely to support impeachment, of course — though 10 current members of Congress (five from each chamber) split their votes on the articles of impeachment.
The Democratic caucus was unified in its opposition to both impeachment and removal in the votes taken in 1998 (impeachment; the 105th Congress) and 1999 (removal; the 106th) across the ideological spectrum.
Republicans were more mixed. Sen. Susan Collins (R-Maine) opposed voting to remove Clinton on the two impeachment counts that reached the Senate. Rep. Collin C. Peterson (D-Minn.) was the most moderate sitting Democrat to vote on the Clinton impeachment. He, too, opposed the articles. Sen. Richard C. Shelby (Ala.), who in 1994 had switched to the Republican Party, voted to remove Clinton on one of the two counts.
The unanimity of the Democratic vote is more obvious below, separating out each member while maintaining the distribution by ideology (as determined by Voteview).
Of course, Republicans had a robust majority in the House in the 105th Congress, about as robust as the Democrats’ now. Members could cast dissenting votes with articles of impeachment still passing. Democrats already saw something of a similar phenomenon with the initial vote to formalize the impeachment inquiry. Several Democrats decided against supporting the inquiry, joining a unified Republican caucus. One can expect some Democrats in 2019 to similarly defect — perhaps including Peterson — with Republicans showing similar party unity to the Democrats 20 years ago.
The shift in impeachment politics is perhaps nowhere better demonstrated than among those six Democratic leaders who announced the charges against Trump on Tuesday and who voted on the Clinton impeachment articles in 1998.
All six voted against each of the four articles targeting Clinton.
Correction: Due to my apparent inability to read my own data, I erroneously wrote that Shelby voted to remove both counts. As the graphics accurately indicated, he only voted for removal on one count.