Hillary Clinton seems to have screwed up this email thing, both by violating some federal archiving rules and then subsequently by botching her initial public explanation of why she didn't. Bad on her.

At the same time, this week saw the release of a new Republican tax plan from Republican Senators Mike Lee and Marco Rubio that's notable for embracing large tax cuts for rich people. That's nothing new for Republicans, of course, but it's noteworthy because last year Lee was pushing his colleagues to move away from tax cuts for the wealthy as the centerpiece of conservative economics.

Of the two stories, Clinton's emails have received by far the most attention. But it's the Rubio-Lee tax plan that actually matters most for the presidential race — and for people's lives.

2016 isn't about email

The Clinton email story has been catnip for political reporters because it doesn't involve difficult-to-master and controversial-to-answer-policy questions. Instead, it offers ample opportunity to engage in ideologically neutral speculation about Clinton's competence as a campaigner. But political stories are interesting only because policy stories are important. The dynastic struggle between the Clinton and Bush families is profoundly boring compared with the dynastic struggle on Game of Thrones. It's only interesting because the real-world stakes are high. And the real-world stakes are high because of things like the Rubio-Lee tax plan.

Currently, the Republican Party has a majority in the US House of Representatives and in the US Senate. In any circumstances where the party wins the White House in 2016, it will maintain those majorities. Those congressional majorities have united around a budget framework that contains the following broad outlines:

Clinton's economic agenda has not yet been outlined in as much detail, but we do have some signs of what it looks like. Her ideas will focus on raising taxes on high-income individuals and big-time investors in order to avoid cuts in programs that serve the bottom 80 percent of the population. She would also like to do a whole bunch of things to increase the time and resources available to help parents of young children take care of them. But even if Clinton wins, she is highly likely to face a Republican House, at least, and so her affirmative agenda is much less likely to pass.

The real stakes in 2016

Consequently, the key question in the 2016 election is whether you think the problem with America is that the system is rigged against the wealthy, whose incomes are unfairly depleted, while coddled working- and middle-class families take advantage of cheap health care and discount college education.

This is not a marginal position, either in American politics or in the economic literature. There is a long line of research that holds that low taxes on the wealthy — and especially on wealthy investors and wealthy heirs and heiresses — are a key driver of economic growth. Lots of people with PhDs and several people with Nobel Prizes in economics believe this. The idea that giant tax cuts for the wealthy paired with reduced assistance to the poor and middle class is the best way to raise living standards is deeply influential.

Regardless of whether it's correct, there is clearly a large number of wealthy Americans who believe it is correct and are willing to invest huge sums of money in trying to make it happen. Moreover, one of the two main political parties in America agrees with them, and its presidential aspirants are beginning to put forward plans for how to make it happen.

By contrast, it's extremely unlikely 2016 is going to be a watershed year for American email-archiving policy. And even if for some reason it is, the actual issue won't change many lives. The disagreement between Republicans and Democrats about tax rates and health-care spending, on the other hand, impacts every single person in the United States, and does so in profound ways.

The GOP's proposed health spending cuts are literally a life-and-death issue for thousands of people, and will seriously impact the personal finances of millions. On the other hand, if the cuts really do boost the long-term growth rate of the American economy in a meaningful way, it could profoundly transform living standards for almost everyone. Digging deep into whether this theory is true is more difficult than "demanding answers" about email protocols. But it's a lot more important.