So here’s where we are: It’s not much of an exaggeration to say that the Senate really is going to vote next week on whether to protect the GOP presidential nominee’s extensive personal wealth and low tax rates.

It’s been widely noted that Romney is probably a far better presidential nominee for the GOP when it comes to down ticket races than, say, Rick Santorum or Newt Gingrich. And that certainly seems right. But Dems are hoping that in one area, at least, Romney will create problems for GOP Senate candidates — his low millionaire tax rates.

Multipe Senate candidates are also pushing the Buffett Rule hard in their own races. Dems point out that even Claire McCaskill, who’s facing a tough fight in Missouri, has been flogging the issue — proof, they say, that it can gain traction even in difficult states or districts. It is already a big issue in the Elizabeth Warren-Scott Brown battle, and will become bigger if and when Brown votes against the measure. And DSCC chair Patty Murray went out with an email today to supporters about the Senate’s planned vote on the measure, which would “make sure that corporate CEOs don’t pay a lower tax rate than the rest of us.”

The push for the Buffett Rule, and the effort to link it directly to Romney, are at the center of the Dems’ strategy of painting Romney as a walking emblem of all the ways the economy and tax system are rigged against the middle class and in favor of the rich.

But Senate Republicans have countered that the issue is irrelevant. Mitch McConnell’s office has been arguing that the Buffett Rule is a show vote that’s designed to fail, and that it will do nothing to bring down gas prices, create jobs, or alleviate economic suffering.

As I noted below, one key dynamic in the presidential race is that Republicans are working hard to separate the issue of tax fairness (where Dems are on offense) from the economy (where Dems may be on the defensive). Obama needs to convincingly sell efforts to combat inequality and tax unfairness as not just a matter of basic morality, but as central to spurring long term investment in the economy, and with it, economic growth and shared prosperity. We may now see that dynamic play out in multiple Senate races, too.