The announcement yesterday by the magazine executive and former presidential candidate, Steve Forbes, that he is endorsing Mayor Giuliani in 2008 and joining the campaign as a national co-chairman and senior policy adviser, crystallizes for us a feeling that has been germinating for quite some time, that Mr. Giuliani is emerging as the candidate in this race for growth-oriented, economic conservatives — and, for that matter, those who aren’t so conservative but comprehend the importance of policies not of managing shortages but of ensuring jobs and growth.

We gained an early glimpse of this in Russell Berman’s dispatch about Mr. Giuliani’s brilliant remarks at the Hoover Institution, where he issued his call to make the GOP the “party of freedom.” We saw it in the interview Mr. Giuliani did this week with Lawrence Kudlow on CNBC’s “Kudlow and Company.” Mr. Kudlow is important because he understands this stuff down to the ground. Mr. Giuliani said flatly: “I regard myself as a supply-sider for sure. I mean, watched Ronald Reagan do it and learned it, saw it work. Taxes get reduced, more revenue comes in.”

In the same interview, the mayor also said, “you lower the capital-gains tax and if you do it smartly, you’re going to end up with more revenues from the lower tax than you do from the higher tax.” And he said, “I think Reagan got it right. I felt that what Reagan did was, I kind of think of it as like cleaning out the forest. You got — the tax code was this big, he got it down to a simple code, reduced the top rates. Kind of leveled out the rates a little so there weren’t as many. The tax code needs a simplification in addition to lowering your sum taxes.”

These columns tend to take nothing for granted in respect of politicians talking tax cuts. Mr. Giuliani did cut taxes as mayor of New York, even with a Democratic City Council and state Assembly, but he still left the city’s residents with one of the highest combined state and local tax burdens in the country. In the case of one of the biggest tax cuts during his tenure, the elimination of the commuter tax, Mr. Giuliani actually opposed the tax cut so vigorously that he brought a lawsuit jointly with the city’s Democratic City Council speaker in an effort to get a court to order state lawmakers to keep the tax in place.

Nonetheless, Mr. Giuliani’s comments to Mr. Kudlow are encouraging. As is the endorsement of Mr. Forbes, who has one of the clearest grasps of the economic issues and tax and economic policy questions of any editor or politician in the country. Mr. Giuliani said yesterday, “Steve and I share an economic vision that embraces supply-side economics, tax relief, and spending restraint.” The election in 2008 will in part be about the war on terror, but it will also be about the ability of the candidates to articulate an optimistic, dynamic, growth-oriented economic policy that builds on a generation-long campaign for tax cuts that was started by President Reagan and is being expanded by President Bush.