Did a hack conservative judge just lay the groundwork for the end of the filibuster? It’s very possible. At least, if the Supreme Court goes along—and if Democrats, as they should, fight back.

The road begins not with last week’s D.C. Circuit Court decision, which if upheld would knock out virtually all recess appointments, but with the Senate Republican plan that Brookings scholar Tom Mann has called “a modern form of nullification.” That was a scheme to prevent some government agencies—the National Labor Relations Board (NLRB), the new Consumer Finance Protection Bureau (CFPB), and others—from functioning by blockading any presidential appointments, using the filibuster to require 60 votes and then keeping the Republican Senate conference united against any nominee. In the case of the NLRB, blocking appointments would mean there was no quorum to do (any) business; leaving the CFPB leaderless would stop the agency from carrying out many of its responsibilities. In both cases, the effect was not only to undermine a Democratic president and Senate, but to bring Republicans something they might not have been able to achieve even if they controlled the White House and Congress: de facto repeal of legislation establishing government regulatory agencies.