(FORTUNE Magazine) – The prospect of a new AT&T/Comcast, a $19-billion-a-year broadband behemoth, should have the Baby Bells quaking. Instead, local telephone companies and other rivals of cable's newest gorilla are likely to cheer (privately, that is) the proposed $72 billion pact.

In fact, none of the companies in this notoriously acrimonious industry seem to be publicly trashing this deal. The reason: If AT&T/Comcast has an easy time in Washington--which is almost a certainty with a Bush in the White House and a Powell running the Federal Communications Commission--many rivals believe that they too will be able to get whatever they want from policymakers.

The days after the deal were telling. SBC Communications of Texas issued a statement reminding lawmakers that the new company would wield significant market power and asking them for "rules that all competitors can play by in the broadband market." (The Bells want out from under regulations that require them to lease parts of their high-speed networks to rivals at deep discounts. The cable industry gets off scot-free in this area.) Nowhere, however, did SBC display its usual tough talk. Same with satellite provider EchoStar Communications, which will likely use the deal to push the government to approve its pending purchase of Hughes Electronics.

Meanwhile, AT&T and Comcast are doing some lobbying of their own, trying to assure lawmakers that the deal would bring long-awaited local-phone competition to consumers. Yet only five months ago, after its first bid for AT&T Broadband, Comcast said it wouldn't deploy local-phone service until it could purchase new, Internet-based technology. Some speculate that the company's newfound fondness for old-fashioned telephony is aimed at assuaging regulators. But Comcast officials say that their aim is genuine, and that they changed their minds while negotiating with AT&T, which has a million customers receiving phone service over cable lines.

These are the kinds of promises that should raise yellow flags in Washington. Indeed, if any deal deserves scrutiny, it's this one--not because of its size, but because of its cast of characters. Besides AT&T and Comcast, two companies that have at one time enjoyed monopolies, former Justice Department target Microsoft is backing the transaction. And what would a cable deal be without AOL Time Warner (FORTUNE's parent)? It has a byzantine partnership with AT&T involving entertainment and cable properties that has yet to be unwound. If complexities like these aren't enough to get their attention, shouldn't regulators be concerned anytime the Bells, AT&T, and satellite companies agree on anything?