Politicians invest for the same reason anyone else does: to make money.

Most won't admit to this. In fact, most don't want to talk about investing at all. But give Rick Santorum credit for being candid about why some of his investments run counter to his policy proposals.

For example: The Republican presidential candidate has campaigned against American companies outsourcing jobs to other countries. He says he has a plan to help bring those jobs back.

But among the stocks he holds, according to his latest financial disclosure (.pdf file), is Fabrinet (FN, news), an outsourcing manufacturer with a workforce located almost entirely in Asia.

Why is it OK for him to invest in an outsourcing company while campaigning against outsourcing?

"My policies over my political career have been very clear -- what we're trying to do is compete, so those companies can manufacture here in this country," he told Bloomberg. Investors put money "in companies that you think are going to help you in your portfolio -- that's why you invest. You make public policy for different reasons."

Unlike rival Mitt Romney, who says he has a completely hands-off approach to investing his millions (read "Where Mitt Romney stashes his millions"), Santorum seems to be hands-on with investment portfolio.

Image: Rick Santorum © Andrew Burton, Getty Images News

Rick Santorum

And there's an interesting parallel between the political campaigns and these politicians' portfolios.

Longtime GOP front-runner Romney, whose campaign coffers are stuffed with cash, has a portfolio befitting his status as one of the richest men ever to run for president. Santorum, whose campaign received a huge boost this month after he won contests in Minnesota, Missouri and Colorado, is the long shot -- and his portfolio can't match that of the guy he's chasing.

Let's take a look at where Santorum invests his money.

Silicon Valley

Santorum invests in 10 stocks directly through his E-Trade account, and many more through individual retirement accounts held with Stifel Financial (SF, news).

Many of the stocks he owns directly are fiber-optic companies based in Silicon Valley, and investment advisers would probably frown at his concentrated holdings in one industry. He owns between $1,000 and $15,000 in shares of JDS Uniphase (JDSU, news), which hasn't been the best market performer; shares have generally hovered between $10 and $15 for the past two years.

(Candidates aren't required to give specific dollar amounts for their investments. Instead, they give a range for their holdings, such as between $100,000 and $250,000 or between $1 million and $5 million.)

Santorum also owns as much as $15,000 worth of each of the following fiber-optic stocks: Opnext (OPXT, news), Finisar (FNSR, news), Oclaro (OCLR, news) and Exfo (EXFO, news). He owns the same amount in Fabrinet, the optical-technology maker that outsources to Asia.

We don't know if Santorum still holds these stocks -- he filed his disclosure in August -- but few have performed particularly well. Opnext is almost a penny stock, and Oclaro has tanked. Finisar, however, has doubled in price in two years to $22, and Exfo has risen 38% in that period to approach $8.

Santorum also directly owns as much as $15,000 in each of the following: oil-and-gas company Rex Energy (REXX, news), telecommunications provider Frontier Communications (FTR, news), and drug-makers Keryx Biopharmaceuticals (KERX, news) and Oncogenex Pharmaceuticals (OGXI, news). Again, none of these stocks have done well in the past two years.

Many sources of income

Santorum easily cleared $1.4 million in income in 2010 and the first seven months of 2011.

While his E-Trade holdings are relatively small, Santorum has made some significant investments in the rental market in Pennsylvania. He owns five rentals in State College, each valued at between $100,000 and $250,000.

Those properties combined produced rental income of between $75,000 and $250,000 for Santorum in 2010 and the first seven months of 2011. But he owed between $350,000 and $750,000 on them on two mortgages with M&T Bank.

He received $239,000 from News Corp. (NWS, news) for his contributor appearances on Fox News in 2010 and 2011, according to his disclosure report. He also received $217,000 as a senior fellow for a conservative think tank, the Ethics and Public Policy Center in Washington, D.C.

He received $23,000 as a columnist for The Philadelphia Inquirer and $84,000 as a talk-show host for a California radio company.

He was paid $395,000 in director fees and stock options on the board of hospital operator Universal Health Services (UHS, news). He was named to the board after he lost a Senate race in 2006 to Democrat Bob Casey Jr.

The rest of his income mostly came from consulting. He received $143,000 advising a Pennsylvania gas and coal producer, Consol Energy (CNX, news). He was paid $65,000 for consulting for American Continental Group and $125,000 for consulting for Clapham Group. Both are lobbying shops, and Santorum's former chief of staff is principal at Clapham Group, Politico reported.