 -- Robert Reich, who served during the administration of former President Bill Clinton as the secretary of labor, will appear on "This Week Sunday morning. Before his appearance, we asked him five questions about former Secretary of State Hillary Clinton and the broader 2016 race for president.

1. I asked you in 2013 if you would support a Hillary Clinton run for the White House and you said, “Yes.” Now that she has officially declared, is she your candidate? Are you backing her over Bernie Sanders, Martin O’Malley and Lincoln Chafee?

RR: I've known Hillary Clinton since she was 19, and have a great deal of confidence in her. At the same time, I agree with Bernie Sanders on much of what he says. But as chairman of Common Cause, a nonpartisan national citizen's group dedicated to getting big money out of politics, I don't feel free to endorse either one of them.

2. Bernie Sanders said he would consider you for treasury secretary during an interview with George Stephanopoulos on “This Week.” Would you serve in his administration if he got elected and asked you?

RR: Sure.

3. You’ve talked a great deal about inequality in this country and were the star of the film “Inequality for All.” In terms of the presidential campaign so far and the issue of inequality, is the messaging of one candidate in particular resonating with you?

RR: I haven't heard anything at all credible from any Republican candidate or likely candidate on how to reverse the nation's widening inequalities of income and wealth. Bernie Sanders has called for busting up the big banks and making higher education free, both important steps. Hillary Clinton has spoken out about inequality, but without many specifics as yet. I hope she takes on Wall Street, whose biggest banks are far larger than they were when they almost destroyed the economy in 2008, and took away the jobs, savings, and homes of millions. And I hope she calls for raising taxes on the wealthy in order to pay for better schools, early-childhood education, and access to higher education.

4. The number of people, according to a new ABC News-Washington Post poll, who see Hillary Clinton as trustworthy has dropped in recent months. Why do you think this is?

RR: She hasn't yet given a convincing explanation for why she used a private email account when she was secretary of state, and why she and her husband have made so many speeches for hundreds of thousands of dollars a pop from special interests that presumably want something in return. In other words, she needs to be more open and transparent about everything.

5. OK, prediction time. Who do you think will be the presidential nominees for both the Republicans and Democrats?

RR: At this point, I'd bet on Jeb Bush or Scott Walker for the Republican nomination, and Hillary Clinton for the Democrats. But, remember, we're still more than a year away from the nominating conventions. Anything can happen.