It’s going to be illuminating to see whether there is any backlash in New Jersey against news that Mayor Bloomberg of New York is scrambling to put an emergency $1 million into the floundering campaign of Mayor Cory Booker to succeed Senator Lautenberg. This news was injected Sunday by Michael Barbaro of the New York Times into a dispatch that ran on page one under the headline “Anxious Allies Aiding Booker In Senate Bid.” Mr. Bloomberg tried something similar in Colorado the other day, and Rocky Mountain voters promptly cashiered his two candidates out of the state’s Senate.

Whether Mr. Bloomberg’s money will be enough for Mr. Booker, we don’t know; the polls are favoring the Democrat beyond their margins of error. All the more reason for the Sun to pony up what pixels it has in an endorsement of the Republican underdog, Steve Lonegan. We don’t gainsay how attractive and smart a figure Mr. Booker is; the former Rhodes scholar stayed with the quest for his dream to be mayor of Newark, and it’s easy to see why, despite his mixed results, he is every liberal’s favorite. But as we watched him in debate with Mr. Lonegan Friday, we also found it easy to see why the underdog has rattled the confidence of the Democratic camp.

Mr. Lonegan, who was twice reelected as mayor of Bogota by wide margins, is smart, articulate, focused, principled, and practical, and he strikes us as the kind of solid and sober citizen we need in the Senate. “A referendum on the Tea Party in Washington” is how Mr. Booker tried in the debate to trans-characterize the race. If that’s what it is, Mr. Lonegan has our vote in extra measure. The kind of conservatism that we need in Washington right now we’d label as less paleo-, neo-, libertarian-, social-, or other hyphenated brand but instead as the kind of constitutional based commitment to founding principles by which the Tea Party is animated.

Only a few weeks ago the idea that such a brand of conservatism could prosper in the Garden State was being widely discounted. The seat voters are getting ready to fill, after all, was held by, in Lautenberg, one of the most doctrinaire liberals in the land. Governor Christie has endorsed Mr. Lonegan but sometimes he has seemed focused more on mending the political image of President Obama than in throwing himself into the race to elevate Mr. Lonegan. The last week of the campaign is a moment when New Jersey would benefit from the governor stepping up. It would be a reminder that the people of New Jersey are a bigger stakeholder in this race than Mayor Bloomberg.