Staggering sums of money are being spent on Tuesday's election.

Expenditures by the presidential candidates, the parties and the primary super PACs already exceed $1.6 billion, and spending may hit $2 billion when it's all tallied.

In California, initiative campaigns alone have cost more than $350 million, with the meter still running, and upwards of $13 million has been spent on a single congressional contest in Los Angeles.

Multimillion dollar donations are becoming commonplace, and the U.S. Supreme Court's Citizens United decision in 2010 opened the gates for corporations and unions to spend unlimited amounts on federal campaigns. And they have spent freely.

Recent election cycles brought us the soccer mom and the NASCAR dad — rank-and-file voters credited with an outsize role in turning elections. This year's addition to the lexicon may be the ultra-deep-pocket donor.

Perhaps 2012 also will be remembered as a year when voters pushed back against the rising tide of campaign spending.

On Tuesday, voters in Mendocino County will decide Measure F, an advisory measure that challenges the notion that corporations enjoy the same rights as individuals.

Measure F calls on the county's elected representatives to enact resolutions supporting an amendment to the U.S. Constitution stating that "only human beings and not corporations are endowed with constitutional rights," that "money isn't doesn't constitute speech" and that campaign contributions can be regulated.

It's past time to address the corrosive role of money in politics, and approval of measures such as Mendocino County's Measure F help fuel the discussion. For that reason, The Press Democrat recommends approval of Measure F.

However, a true solution must address more than corporate political spending. Many of the biggest super PAC donors aren't corporations. They're wealthy individuals such as casino magnate Sheldon Adelson and retired hedge fund executive James Simmons. Others on the top 10 list include the Republican Governors Association, the United Auto Workers, the National Education Association and the Service Employees International Union.

All of these donors are identified. Congress has failed to address gaping loopholes that allow donors to remain anonymous by turning nonprofit educational foundations into the functional equivalent of political action committees.

Meanwhile, an older U.S. Supreme Court ruling, Buckley v. Valeo, in 1976, facilitates unlimited spending by individuals via independent expenditures, super PACs and initiatives. No fewer than seven propositions on Tuesday's ballot are funded by deep-pocket donors, some of whom wouldn't be slowed down at all by the amendment envisioned by Measure F.

The bottom line is this, campaign finance is a messy thicket where it's too easy to hide money as well as the source and motive of many of the messages delivered to voters during campaign season.

Proposition 32 is a one-sided approach, effectively limiting only unions. An amendment that only addresses corporations isn't a fix either. Faster and fuller disclosure would be valuable steps toward transparency. A constitutional amendment may be needed to overturn Citizens United and, perhaps, to allow limits on campaign spending. The discussion should begin now, and approval of Measure F in Mendocino County could help start that discussion.