Should corporations and other special interests dumping money into federal elections be forced to disclose their spending? That’s the question the US Senate will take up today—or, more accurately, it will take up the question of whether to take up that question. (A Republican filibuster blocking a vote is virtually guaranteed).

When the Supreme Court opened up the cash spigots with Citizen’s United v. Federal Election Commission, allowing unlimited corporate spending on federal elections, it also stressed that disclosure was important. The decision said “transparency enables the electorate to make informed decisions and give proper weight to different speakers and messages.” Last year, even Justice Antonin Scalia wrote: “Requiring people to stand up in public for their political acts fosters civic courage, without which democracy is doomed.”

In fact, Justice Anthony Kennedy seemed to think that such disclosure already existed, boasting in the Citizen’s United decision that “a campaign finance system that pairs corporate independent expenditures with effective disclosure has not existed before today.” That puzzled most observers, since virtually no disclosure apparatus exists around corporate donations to nonprofit outside groups.

But the bill introduced in the Senate today would create one—requiring an online disclosure within twenty-four hours of any expenditure over $10,000. Some reports have characterized today’s DISCLOSE bill as overturning Citizen’s United, but in fact it’s consistent with the spirit expressed in the decision.

The bill has been stripped down from what was introduced in 2010, in an apparently unsuccessful effort to win bipartisan support. (Remember earlier this year when Senator John McCain made some noise about supporting the DISCLOSE Act; he has taken no position on today’s vote, however). This version drops requirements that leaders of outside groups must endorse the message on-air during an advertisement, and that the ads list the top funders. It also wouldn’t take effect until January 2013—after this year’s elections.

The idea is simply to put senators on the record on where they stand on making outside money transparent in elections.

Actually, however, as Dan Froomkin notes, fourteen Republican senators are already on the record supporting campaign finance disclosure. That used to be a popular conservative position; George Will once proposed making campaign finance law seven words: “no cash, full disclosure, no foreign money.”

But Republicans have quickly shifted their stance in recent years, culminating in Senate majority leader Mitch McConnell’s recent rabid denunciations of the DISCLOSE Act as “un-American.” This is why the latest vote is expected to fail. As Senator Al Franken wrote in an op-ed at the Huffington Post today:

Today—unless, again, I’m pleasantly surprised—all the Republicans in the Senate, including those who have specifically called for more disclosure in our system, will once again block it from proceeding.

In our country, a few have a lot more money than the rest. In our political system, money is power. And that means a few can have a lot more power than the rest. That’s bad news for everyone else—and for our democracy itself. And although we’ve always argued over how best to prevent that from happening, today’s vote is yet another sign that some have decided to embrace that shift instead.

When the Senate vote fails, there are still other ways to force disclosure. The Securities and Exchange Commission could require publicly traded companies to disclose their donations, an idea that has support with at least one SEC commissioner. A reformed FEC could get the job done as well.

UPDATE: As predicted, Republicans in the Senate wielded a filibuster to prevent a vote on the DISCLOSE Act. Every Republican Senator–including potential supporters like Senators McCain, Lugar, Brown (MA), Collins and Snowe voted against it. Every Democrat voted for it (except Majority Leader Harry Reid, who voted against it for procedural reasons, so that he might re-introduce it later). The bill received 51 ayes and 44 noes, nine short of clearing the filibuster.