The lift that 9-9-9 would provide to a candidate in the Republican primaries would turn to lead in the general election.
This conundrum is why, thus far, Romney has damned 9-9-9 with very faint criticism, saying in the last debate only that "simple answers are always very helpful, but oftentimes inadequate." What? Romney's view is that 9-9-9 is "helpful" but "inadequate"? What would be "adequate," then? 10-10-10? 11-11-11? This vague and confusing position can't be sustained over the long run.
Primary Perils
Perhaps what gives Romney particular angst in dealing with the 9-9-9 plan is the history of rough waters that have buffeted Republican front-runners when trying to navigate the primary season's recurring flat-tax tidal wave.
What Romney must particularly avoid is the mess that nominee Bob Dole got himself in during the 1996 campaign. Dole first spent the primary season battling Steve Forbes's flat-tax plan, only to reverse himself and embrace the flat tax when he added Jack "15 percent" Kemp to the ticket. He then distanced himself from his running partner and relegated Kemp to obscurity in the final month of the campaign, when it became clear that the tax plan was a political liability.
If Romney or Perry takes a strong stand against the Cain plan, they will make the primary race more difficult for themselves, at a time when neither can afford to antagonize the activist voters who dominate the process. But if they try to make Cain's plan their own, they are signing on to a program that will sink them in the general-election campaign.
Ron Klain, a former chief of staff to Vice President Joe Biden and a senior advisor to President Barack Obama on the Recovery Act, is a Bloomberg View columnist. He is a senior executive with a private investment firm. The opinions expressed are his own.