Yes, but how will Clinton persuade Republicans to vote for all this?

Yes, but how will Hillary Clinton get Republicans to vote for any this?

That’s the question that kept running through my mind while I listened to Hillary Clinton’s announcement speech Saturday morning. Clinton name-checked almost every center-left policy idea in existence: universal pre-k, guaranteed paid sick days, massive investments in clean energy, rewriting the tax code, raising the minimum wage, and so on.

Many of these ideas are good. But there’s a Democrat in the White House right now. He supports these ideas, too. And yet, they languish in press releases and stalled legislation. How will Hillary Clinton make them law?

This might be a lot to ask from a campaign announcement speech — or from any campaign speech. Grand promises are the coin of the realm. But as President Obama has found out, a campaign that dreams too big can set up a presidency that disappoints the very people it once inspired. If Clinton is going to rebuild the excitement Obama harnessed in 2008, she’s going to have to convince disillusioned Democrats that she can make good on her promises.

Whether Clinton actually has that theory will be the question lurking behind the policy speeches aides say she will deliver in the coming weeks. No worker gets a wage hike because of a minimum wage proposal. No mother gets paid sick days from a white paper. In this, the location of Clinton’s speech was telling: Franklin Delano Roosevelt is remembered not for what he proposed on the campaign trail, but for how much he did in office.

Obama’s 2008 campaign was less about his policies than it was about his theory of change. He argued that a new form of politics, a less polarizing form of politics, could create a new kind of political movement — younger, larger, more diverse — and that movement would be big enough, and powerful enough, to force Washington to work again.

He was half right. His campaign did build that movement, and that movement gave him the historic Democratic congressional majorities that passed the stimulus and Obamacare and the financial reforms into law. Obama’s theory of change worked for two years. And today, about 16 million more people have health insurance because of it.

But then Republicans took back the House, and that basically marked the end of Obama’s legislative successes. Obama’s movement, it turned out, didn’t much care for midterm elections, and his administration quickly proved more polarizing than the ones that came before it. The final years of Obama’s presidency have been a repudiation of its early promises: where Obama once vowed to make Washington work together, he is now finding new and ever more aggressive ways for the president to act alone.

Due to geography and gerrymandering, Clinton, too, will almost certainly face a Republican House. But she is unburdened by Obama’s early optimism: she harbors no illusions that Republicans will work with her to raise taxes on the rich or guarantee paid leave for the poor. And she has had eight years to watch both Obama’s successes and failures, and to consider what she would do differently.

So what has she learned? Why should voters, disillusioned by the grim politics of Obama’s second term, believe a Clinton presidency will be different?

Hillary Clinton keeps telling us she’s a fighter. And I believe her. I think pretty much everyone does. But the question for a fighter isn’t whether she’ll fight. It’s how she’ll win.