Once upon a time, a Supreme Court nomination was largely noncontentious. The general approach of the Senate’s advise-and-consent mandate was that the primary determination of who should earn a seat on the bench was determined by voters in the most recent presidential election. Nominees were often simply confirmed on a voice vote, sent by the Senate to lifetime appointments across the street with little debate.
As you probably noticed, that is no longer the case. Not only are voice votes extinct, so are broadly bipartisan confirmation votes. The last Supreme Court nominee to have received more than 70 votes was Chief Justice John G. Roberts Jr., nearly 20 years ago. The six justices confirmed since have averaged less than 60 — and the last three were confirmed thanks to the 2017 decision to make Supreme Court nominations exempt from the filibuster.
What’s happened is what’s happened to American politics broadly: Bipartisanship has declined as partisanship has increased.
We can visualize this. I took the 14 contested confirmations since the beginning of Ronald Reagan’s presidency and contrasted each senator’s vote on the nomination with his or her ideology score as measured by Voteview. Since we now expect members of the president’s own party to support his nominees and for members of the opposition to, well, oppose those nominees, I’ve highlighted those votes that went the other way: members of the president’s party who voted no and members of the opposition who voted yes.
(Voteview measures DW-NOMINATE scores for ideology, which runs on a scale from minus-1 to 1. To compare senators regardless of party, what’s shown is the absolute value of each ideology score. A Democratic senator who’s as far from the middle — zero — as a Republican would have an equivalent ideology score.)
You’ll notice right away that the number of party-defying votes has evaporated. Senators are less willing to vote against their president or for a president of the opposing party. (By the way, independents are counted as members of the party with which they caucus.) But notice, too, that the density of more-moderate senators has declined. There are a lot more circles lower on each chart in recent nominating votes than there were for Sandra Day O’Connor.
If we consider any score of 0.3 or lower the “most moderate” part of a Senate caucus, you can see how the percentage of senators within that range has declined. But you can also see how that decline hasn’t been even — the decline has been much greater among Republicans.
It’s always been the more moderate members of the president’s party that have been more likely to vote against his nominees. But it used to be the case that members of the opposing party who supported a nominee were not generally much more moderate than their party’s caucus overall. That changed with President Donald Trump’s nominees.
That’s in part because so few members of the opposing party now support a president’s nomination, so we have a more polarized Senate (particularly on the right) with fewer moderates who are crossing the aisle to support or oppose a president’s nomination.
The nomination of Judge Ketanji Brown Jackson that’s currently being considered by the Senate seems unlikely to yield an extended, contentious fight. She’s been nominated by a Democratic president to replace a more-liberal justice. The balance of power on the court will not change.
But it seems very unlikely that the recent partisan pattern above will be broken. That is, even if not particularly contentious, it seems quite unlikely that Jackson will get a significant number of Republican votes.
After all, there aren’t many moderate Republican senators left.