It should come as no surprise that certain companies and industries stand to gain if certain presidential candidates win. After all, many are quick to point out how well oil companies have done under the current administration. Look at these market-trouncing gains for ExxonMobil (NYSE: XOM), for example:

  • 2003: 21%
  • 2004: 28%
  • 2005: 12%
  • 2006: 39%
  • 2007: 24%

Believe it or not, those returns actually lagged much of the rest of the industry!

So, how might election results in November affect various investments? At seekingalpha.com, Gary Gordon focused on one particular candidate, picking out some "Obama-friendly" ETFs. (ETFs, or exchange-traded funds, combine features of individual stocks and index funds. Read all about them and how they offer some valuable advantages over traditional mutual funds in our ETF Center.)

For starters, given Obama's interest in alternative energy, it was suggested that ETFs focusing on the sector, such as the Market Vectors Alternative Energy ETF and the Powershares Global Clean Energy Fund, might fare well. The former contains stocks such as First Solar (Nasdaq: FSLR) and Suntech Power (NYSE: STP), while the latter is invested in the likes of Cree and MEMC Electronic Materials (NYSE: WFR).

This is just the tip of the iceberg. Spend a little time reading and thinking about the candidates' positions on lots of issues, and you'll likely see a lot of possible opportunity -- or danger, depending on your holdings. For example, there's a lot of talk about overhauling our medical system and providing more health-care coverage for more Americans. This results in a lot of uncertainty for pharmaceutical companies like Merck (NYSE: MRK) and Pfizer (NYSE: PFE), as well as other companies that deal with health care. Despite the confidence we might have in continued sales growth for such enterprises, future profit margins suddenly seem less clear.

In another direction, think about the war in Iraq. Decisions made at the top levels of government can have a big impact on defense contractors like Lockheed Martin (NYSE: LMT).

There's money to be made, if you can tell which way the wind is blowing. But political considerations are just one thing you have to take into account when looking for long-term winning investments, although they're definitely important to keep in mind.

Suntech Power is a Motley Fool Rule Breakers recommendation. To learn more about companies that lead the way in pioneering new industries, take a free look for 30 days.

Longtime Fool contributor Selena Maranjian does not own shares of any companies mentioned in this article. Try our investing services free for 30 days. The Motley Fool is Fools writing for Fools.