Such a change wouldn’t stem the flood of outside money deforming the political system, but it would give candidates an alternative way to run — and provide not-so-rich Americans a greater sense that their voices can be heard. It is the foundation on which other anti-corruption efforts rest, reformers say, with a warning that if lawmakers don’t address this problem, their credibility will remain in the toilet.

The data suggest that the public has an appetite for taking on campaign finance. A Pew Research poll from May found that 77 percent of Americans favor “limits on the amount of money individuals and organizations” can spend on campaigns. (This includes 71 percent of Republicans and Republican-leaning independents.) Sixty-five percent believe that new laws could effectively reduce the influence of money in politics.

At this point, the hunger for reform is so fierce among the Democratic base that the caucus will need to work to temper expectations. While H.R. 1 is near the top of the to-do list of the incoming House speaker, Nancy Pelosi, the package will take a while to make its way to a floor vote. At least five committees have oversight of pieces of it, and even among Democrats there are competing visions for various provisions that must be worked through. Democratic House leaders are hoping to get a bill passed early in the year. And then it is likely to go nowhere fast.

One reason H.R. 1 can be so big and bold is that it is mostly an expression of what Democrats would like to do rather than what has any real shot at moving through this divided government. Even staunch fans of the measure expect the Republican majority leader in the Senate, Mitch McConnell, to jam it up in his chamber. The phlegmatic Mr. McConnell may not get worked up about much, but over the years he has consistently displayed a fierce passion for strangling anything resembling campaign finance reform.

The package could prove awkward for Republican members in other areas as well. For instance, measures to make voting easier might be a hard sell in a party that appears to have so vigorously committed to curtailing voter access.

Realistically speaking, enacting even pieces of a bill like H.R. 1 is more of a medium- to longish-term legislative goal. But this does not diminish the urgency of passing the package in the House as a declaration of Democrats’ commitment. Its champions seem to grasp this. Mr. Sarbanes expressed optimism that serious revisions could be achieved within a couple of election cycles — but only if Democrats move quickly to get people fired up and then “keep the pressure on.”

Even the most ethically bankrupt politician can spout drivel about “draining the swamp.” For the next couple of years, Democrats’ challenge is to keep this issue hot enough to make life uncomfortable for reform foes like Mr. McConnell — and to make clear to voters what must be done if they want to take this crusade beyond one chamber of Congress.

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