If all goes according to their plans, Democrats will regain unified control of Washington by the end of 2020. But once the excitement wears off, the new president could enter 2021 facing a governing crisis.
Right now, there are two political crosswinds facing Democrats that will complicate any plans were they to retake power. There is a growing sentiment among the activist liberal base that Democrats need to be bolder in both their policies and their tactics. But the reality of the Senate map will force them to curb their ambitions.
Liberals have been increasingly frustrated by what they see as a tendency among their party to be overly deferential to norms while Republicans are ruthless in pursuit of their agenda (the mirror image of conservative complaints about the Republican Party). This sentiment has only grown under President Trump, reaching a fever pitch during the bitter confirmation battle of Supreme Court Justice Brett Kavanaugh. Now, it has become more routine for liberals to float the idea of impeaching a sitting justice or packing the court if they retake power.
Democratic presidential nominees will be under significant pressure to prove not only that they are willing to fight like hell to crush Republicans by any means necessary, but also that they are willing to embrace a sweeping domestic policy agenda. We've seen this in the way that Democratic senators tripped all over each other to see who could be the most angry and vicious during the Kavanaugh fight. We've also seen this in how leading 2020 contenders have openly endorsed ideas such as socialized healthcare and federal job guarantees that never would have been touched by previous candidates.
The problem is that this trend is incongruous with the Senate map. In 2016, Trump carried 30 states representing 60 Senate seats. Even under the best of circumstances, Democrats are likely to get out of the next two election cycles with a very narrow Senate majority with a handful of swing senators representing states that tend to vote Republican.
In 2018, Democrats are defending five seats in states that Trump won by an average of 27 points. Even if they hold all of them, to control the Senate, they'll still have to take over seats in Nevada and Arizona. If they lose any one of those seats, they'll have to win in either Texas or Tennessee (or both, if two of the solid Trump states fall into Republican hands).
Should Democrats fail to capture the Senate this year, they will face better odds in 2020, but, as detailed in an earlier post, the task will not be easy. This is especially true because they're all but certain to lose the Alabama Senate seat as long as Republicans avoid nominating somebody named Roy Moore. No path to a Democratic Senate majority can avoid carrying traditionally Republican states, and any larger majority would require winning seats in deep-red states.
This does not mean that a unified Democratic government will be unable to get anything done. They will pass regulations and confirm judges and make incremental policy gains — perhaps they will be able to tinker around the margins to expand Obamacare or scale back some of the Trump tax cuts or increase the minimum wage. What they are very unlikely to be able to do is pass a transformative social agenda.
Making such an agenda a reality will require not only finding a majority in the Senate that will support liberals on the policy front, but who will be willing to embrace their tactics as well. More specifically, getting 51 votes to pass single-payer healthcare is hard enough, getting several red-state Democrats on board with nuking the legislative filibuster (or jamming it through the reconciliation process) is an even-heavier lift. Remember that Sen. Joe Manchin, D-W.Va., voted against Democrats' more limited nuking of the judicial filibuster in 2013.
During the Obama era, Republican leaders campaigned on lofty promises about reining in spending and repealing Obamacare, only to frustrate their base by acknowledging their limitations once they gained power. This contributed to the perception on the Right that Republican leadership was weak, a perception that Trump masterfully exploited during the primaries.
Any 2020 Democratic presidential candidate promising to go to the mattresses to advance a sweeping progressive agenda is going to be setting up the party's base for bitter disappointment.