CONGRESS TRIED to limit the influence of wealthy political donors in successive reforms over several decades. The Supreme Court undid a lot of that work in successive rulings over the past decade. Now, instead of shoring up the system the justices weakened, Congress is helping in the demolition.

Lawmakers are on the verge of approving a massive budget deal. Included is a landmark weakening of the rules on how much individuals can give to political parties. According to various rules, individuals currently can donate up to $129,600 per year to various party organs. Congress imposed limits to end the era of “soft money,” when politicians raised massive sums for political parties that got diverted into campaigning.

In contrast, Congress’s pending budget deal would allow individuals to contribute $777,600 per year in donations to several separate party funds. On paper, the parties would be limited in how they spend the additional money they would raise: They would be allowed to solicit big donations for nominating conventions, to build larger war chests for recounts or “other legal proceedings” and to finance construction of “one or more” headquarters buildings. Our guess is that the parties would find ways to siphon these funds into infrastructure that’s useful during campaigns and that they would spend on all sorts of “other legal proceedings.” Even if parties didn’t game the rules, restricted money would still free up unrestricted cash for other things.

Members of Congress have reason to find the limit increase distasteful: It conjures images of the nation’s leaders having more leeway to shill for big checks, personally and directly. Even so, it’s not worth upsetting the budget compromise to prevent the rules change. That’s in part because things were already so bad before it was proposed. The Supreme Court had already given politicians the ability to ask for large donations for joint fundraising committees. Worse, entities beyond the control of candidates and parties have been spending massive amounts of unlimited and secret “dark money” in recent elections. Though this money is not supposed to be spent in coordination with candidates, campaigns are finding ways around that restriction.

Because the court left a deeply imperfect system in the wake of its decisions, the priority must be for Congress to find new ways to improve it. Ideas include more and better public financing of campaigns, which would limit or remove the necessity of constant fundraising, and restricting the ability of candidates and party leaders to solicit big checks. One idea should be obvious and universally acceptable: requiring more reporting about who is spending what to promote which candidate or party. If rivers of money are to keep flowing, voters should at least be able to detect the influence buying that’s likely to follow.

There’s no good argument against this idea. Republicans such as soon-to-be Senate majority leader Mitch McConnell, in fact, said they were for more transparency — before they killed a transparency bill in 2012. Now that the GOP will be in charge of Capitol Hill, they should consider reviving their old position — instead of continuing to dignify their indefensible new one.