As the week comes to a close, a few tidbits to ponder on a sunny Sacramento afternoon…

* Homeless, But Where?: Some new estimates on the size of the nation’s homeless population are the focus of debate here in California. Meantime, that same estimate finds more without a home in Fresno… than in San Francisco. On this weekend’s newsmagzine edition of The California Report, we examine both topics… with a look at law enforcement raids on homeless encampments in Fresno, reported by my colleague Sasha Khoka.

* White House Hopefuls: Presidential candidates are on their way back to the Golden State over the next few days: Democrat John Edwards is in Fresno today, Berkeley on Sunday, and LA on Monday… Hillary Clinton is in LA on Saturday… and Republican Rudy Giuliani also heads to LA on Monday.

* Yes, That’s How Much It Weighs: Several emails have arrived in my box questioning the accuracy of the math in this week’s posting (and this week’s radio piece) on just how big of a carbon footprint is left by Governor Schwarzenegger’s travels in a Gulfstream jet.

These readers and listeners doubt that a gallon of jet fuel can be responsible for 28 lbs. of carbon dioxide emissions. “The right numbers should be used when criticizing [the governor’s] actions,” wrote one person. Another asked: “Did you do some research on what the environmentalists said, or did you just use their information ‘as is’?”

We did, in fact, do research. The layperson’s explanation: the actual jet fuel is not the only source of fuel for the engine itself. It also uses gases in the air as fuel– namely, oxygen. Thus, a carbon will attach itself to two oxygens to create CO2. And because oxygen is a little heavier than carbon (16:12 atomic weight), the mass of CO2 emitted is actually heavier than the original jet fuel.

Our numbers were based on data from the U.S. Department of Energy, plus an additional calculation from the Sierra Club suggesting that the CO2 emissions should also include the emissions created by the refining of each gallon of jet fuel. Today, we checked our math with faculty members at both CSU Chico and UC Davis. Both agreed with our number… 28 lbs. of CO2 per gallon of jet fuel… and one even opined that the number was probably “conservative.”

The fastest growing group of California voters, contrary to what was said a few weeks ago, will not be allowed to vote for one of the major party’s presidential candidates next year.

Two weeks ago, the new chairman of the California Republican Party, Ron Nehring, told reporters that he would authorize voters registered as ‘decline to state’ as eligible to cast ballots in next year’s GOP presidential primary.

Not so fast, it seems.

Now, attorneys for the state Republican party have clarified that Nehring can’t unilaterally make that decision. And as GOP blogger Jon Fleischman points out this morning, even if the party wanted to make the change… there probably isn’t enough time under national GOP rules to do so.

Democrats, of course, love the disparity. Their state party leaders have agreed to allow so-called ‘DTS’ voters to cast presidential primary ballots in 2008.

There’s no real way to know how this will play out. Might Democratic candidates need to devise strategies that help them reach out to middle-of-the-road moderates? Might more conservative GOP candidates now be better suited to win in the Golden State?

For now, it’s all a good parlor game. But at least we know the rules.