Republicans have inched ahead in the generic ballot, according to the Real Clear Politics polling average. These surveys measure which party voters prefer to see control Congress after November's midterm elections.
The midterms have often delivered sharp rebukes to the White House and brisk reversals in partisan average. Two years after Bill Clinton won the presidency and ushered in three-fifths majorities in both houses of Congress, Republicans erased those majorities, gaining 52 seats in the House. Barack Obama's election in 2008 helped Democrats win even bigger majorities. Two years later, Republicans added 63 House seats.
Republican losses in the midterm elections of 2006 and 2018 foreshowed unified Democratic control of the federal government's elected branches. But voters ultimately turned against what Democrats did with that control. We've repeatedly seen blue waves followed by red ones, claims of permanent Democratic or Republican majorities refuted within an election cycle or two.
But this change has increasingly made the parties more resistant to changing themselves. All they now need to do is wait for the party in power to become unpopular and the voters will have no choice but to vote them back in again.
That's why Democrats are shining a bright light on Donald Trump's influence over the GOP — they are trying to remind the electorate about what it disliked about Republicans that made them hand the White House to Joe Biden in the first place. But it is not clear that when weighed against inflation, border insecurity, violent crime, and the third year of the pandemic if this will be good enough.
Democrats — who were, if anything, to the left of the ones voters rejected in 2010, 2014, and 2016 — won power, however narrowly, because the alternative was Trump. Some of these Democrats may be replaced by just-as-Trumpy Republicans because they are the only other option.
The biggest exception was Clinton, who sought to systematically address the Democrats' weaknesses on crime, welfare, and values during the 1990s. There is also a slight degree to which Trump distinguished the GOP from its George W. Bush-era incarnation, though he clearly added some new baggage of his own.
But the end result of the past five years of political tumult could continue the polarization as too-woke Democrats and low-brow populist Republicans turn off vast swathes of the country, each side yet waiting for the other to screw up.