Not always, three cheers!
In the DFL (Democratic) Gubernatorial Primary in Minnesota, two of the three candidates were millionaires and spent like their pockets were bottomless. Mark Dayton got the most votes, and Matt Entenza got the least. In fact, Entenza who had ads everywhere – door hangers, stickers on newspapers, Web ads for anybody with a Minnesota URL - came in a distant third. So distant that he conceded 90 minutes after the polls closed. Margaret Anderson Kelliher, the endorsed candidate, spent far less than the other two candidates and came in a close second to Dayton. Close enough that she waited until the middle of the day after to concede.
As obscene amounts of money are spent by candidates and special interest groups, one wonders how anybody can even listen to all the campaign drivel. But listen people do, and often uncritically. Missile gap, anyone?
If you don't like the amount of money being spent, you can look up various races at http://www.opensecrets.org. You can see how much was raised from donors and from what kind of industries. Armed with this information, you can judge how much a candidate may follow your interests or be supported by people who do not share your interests. For example, if a candidate gets lots of money from trial lawyers, you may be happy because you think corporations have too much edge over individuals in courts. If a candidate is supported by labor unions, you may be unhappy because you don't like unions. The kinds of donors a candidate has may speak more loudly and accurately than any speech or ad. Similarly, those funding ads in support of or opposition to a candidate may speak volumes about that candidate.
Of course, surprises can be in store. Much was written about Tea Party support for Sen. Scott Brown of Massachusetts. From what I've read he looks more moderate than many would expect.
And the last piece of good news is in a blog Andrew Kreighbaum wrote for Open Secrets; the title that includes "Voters Reject Wealthy Candidates". He wrote, "As the Center for Responsive Politics has found, self-funded candidates, even with their wealth, typically lose when running for federal-office.