The first question in Sunday’s Democratic primary debate was: “President Obama came to office determined to swing for the fences on health care reform. Voters want to know how you would define your presidency? How would you think big? So complete this sentence: in my first 100 days in office, my top three priorities will be — fill in the blank.”

All three candidates answered as they had been encouraged to, by describing grand changes in society that would require legislation to accomplish. None mentioned that conservatives have almost a 100% chance of controlling the House, the judiciary, and most states.

I wouldn’t criticize their approach to answering the question. If they had stuck to politically realistic answers, they would have allowed the other party to narrow the scope of discussion and debate. Also, it was illuminating to understand the differences that emerged when the candidates discussed legislation. For instance, are the Affordable Care Act and Dodd-Frank hard-won and fragile victories to be protected with strongly affirmative rhetoric (Clinton), or mere promissory notes demanding to be redeemed with better laws (Sanders)? Are almost all political dysfunctions traceable to campaign money (Sanders), or could skillful leadership within the current system improve things (Clinton)? Finally, it would have been defeatist for these candidates to offer realistic plans for their first 100 days. That would have undercut progressives’ efforts to win down-ballot races and would have converted a prediction into a self-fulfilling prophesy. In other words, it would have been bad leadership.

And yet, as someone deciding which candidate to choose, I am interested in what each candidate would actually do in office (as well as the more pressing question: Who has a better chance of beating the Republican nominee?). At least in the first two years, they would be able to do virtually none of the things they proposed in the debate. Any of them would veto assaults on the Affordable Care Act and negotiate a budget deal that retains most of the status quo. But some choices would confront them:

What unilateral foreign policy decisions to make. This is the area where Congress has–perhaps unfortunately–the least scope, although the national security apparatus has a great deal of say, and it’s not clear that the president really does decide. Dovish progressives have a hard choice in ’16, because Clinton has a hawkish record and Sanders has no experience managing the military and security agencies.

What legislation to propose to Congress first. Three options to send to the Hill are: 1) Widely popular but small-bore bills that can pass and establish a record of accomplishment. 2) Wedge issues: bills designed to catch the House Republicans between their constituents’ opinions and their party orthodoxy. Or 3) grand visions of alternative health or justice systems. These would fail but could possibly alter the terms of public debate. It’s a hard choice.

What executive orders to issue. Note that President Obama seems intent on using that authority to its full in his final year, and he may not leave a lot of attractive options for his successor.

Whom to nominate for a wide range of offices. Within many domains of policy, a Democrat has genuine choices. For instance, she or he could nominate an education reformer enamored of metrics, accountability, and competition (continuing the status quo) or switch to someone who prefers to give teachers autonomy and resources. There is plenty of room within the legislative framework of the Elementary and Secondary Education Act to push in either direction. In the economic agencies, there is a choice between mollifying Wall Street and the markets or regulating them aggressively.

In making appointments, the president also gets to choose leaders with a range of personal profiles. Any Democratic president will look for racial and gender diversity, but how to weigh ideological, religious, generational, and regional diversity? Should most cabinet secretaries have extensive experience as CEOs of large bureaucracies so that they can run things smoothly, or should they be thinkers and advocates?

I enjoy the debate about long-term directions for progressive politics and the nation, but we should probably ask the candidates how they will resolve the decisions that they will actually face.

(Washington) In Hacking the Electorate: How Campaigns Perceive Voters, Eitan Hersh shows that candidates and campaigns obtain their knowledge of us, the citizenry, by analyzing voter files. They don’t know the truth about us; they know what the voter files say about us.

That means that getting on the voting rolls is a source of power. Once you’re on, the political class becomes interested in you. They measure and model and predict your preferences and behaviors. Your vote may not make a marginal difference in the electoral outcome. After all, most elections are lopsided victories. But even if you are part of a large majority or a small minority, the candidates will pay attention to you if you’re in the voter files, and they won’t even see you if you aren’t.

This is an argument for registering and voting that may not be easy to convey, but it has the advantage of being right.

Don’t campaigns learn what the whole population thinks from polls? The answer is: sometimes. Polls are mainly conducted for high profile races. It’s a pop-culture myth (see “The Good Wife”) that ordinary candidates do any significant polling. Besides, we are in the midst of a data revolution in which companies, governments, and politicians are shifting away from random samples to datasets that track all of the relevant behavior–every purchase on Amazon, every Web search, or every vote. These datasets are far more powerful than surveys for predicting and influencing people. In particular, voting files are powerful because: (1) public policy requires the collection of more data on voters than is strictly necessary to run an election, (2) voter files can be merged with commercial records, and (3) analysis of such data is becoming both more sophisticated and more user-friendly. (I take all of this from Hersh.)

Don’t campaigns learn about the public by talking to people? They used to rely on skillful, experienced neighborhood-level volunteers to provide information about the electorate. That whole infrastructure has been hollowed out by money and technology. Of course, there are still volunteers. But they come forward to work on particular campaigns. Few have deep and accumulated knowledge of local voters. The best way to harvest what they learn during a campaign is to require them to upload their observations about specific citizens to the voter files. Meanwhile, the candidates spend their time talking to donors. The voter file is how the campaign learns who you are–which means that you should make sure you’re on it by voting.