UPDATED AT 5:10 P.M. -- DIRTY TRICKS IN POLITICS BEING WHAT THEY ARE, IT ISN'T SURPRISING THAT THE ORIGINAL TOOL WAS CORRUPTED TODAY. WE HAVE CHANGED THE LINK SO THAT USERS WILL DOWNLOAD THEIR OWN UNIQUE VERSION OF TOOL. -- th

What does each of the candidates in Ventura County's 26th Congressional District need to do on June 5 to make it to the general election ballot in November? For instance, in order for Democrat Julia Brownley to finish first or second and therefore advance to November, what percentage of the Democratic vote will she need to capture? Or, in order to be competitive, what percentage of the GOP vote will Republican-turned-independent Linda Parks need if she's to have a chance to finish in the top two?

And how will voter turnout affect those calculations?

Those are the variables, and slight changes in any of them can decisively change the order of finish.

I've speculated about some of these potential scenarios in my writing about this race, which prompted Camarillo software guru David Maron, who consults candidates in local nonpartisan races, to create the fascinating tool at the bottom of this post. Maron sent me his customized Excel file that allows the user to try out different scenarios. It immediately calculates the final vote totals to reflect whatever turnout and share-of-partisan votes are being tested.

Maron sent me the tool and invited me to plug in numbers as I saw fit. For the voter turnout by party, I used the countywide turnout percentages from the June 2010 primary -- 33 percent among Democrats, 47 percent among Republicans and 11 percent among nonpartisans.

Then I put in some random guesses as to how each candidate might fare among each of the voter groups. Those guesses are based in part on the limited polling data I've seen, in part on how much money each candidate has raised, and in part on their overall name ID and endorsements. They could be wildly far off.

You can see how my calculations worked out below (you have to toggle around a bit to see the whole chart). And best of all, you can click on the link to access a spreadsheet so that you can try out your own scenarios.

A slight change in the variables can make a huge difference. For instance, I calculated what would happen if Parks is able to win 30 percent of the GOP vote, 15 percent of the Democratic vote and 60 percent of the nonpartisan vote. In the same model, I gave Brownley 62 percent of the Democratic vote. Under that scenario, Brownley edges out Parks by about 2,000 votes for second place.

But it doesn't take much of a change to move Parks up to second. For instance, giving her two more percent of the Democratic vote (17 percent), giving Jess Herrera two more percent (bumping him from 13 percent to 15 percent) and reducing Brownley's share of the Demcoratic vote to 59 percent results in Parks beating out Brownley for the second spot by about 300 votes.

I encourage you to give it a try.

To be sure, it's nothing more than a parlor game, but it does provide some clues as to what the potential campaign strategies of the various candidates need to be. It will be important, for instance, for Brownley, Herrera, David Cruz Thayne and Al Goldberg to try to keep Parks' share of the Democratic vote as low as possible. That likely means attacking her in mailers to Democratic voters using arguments designed to paint her as too conservative. It clearly will be important for Parks to maximize her share of the Republican vote, which likely means she will need to appeal heavily to Republican women and to GOP voters in her home base of Thousand Oaks. And what about Tony Strickland, the only Republican in the race? Can he afford to sit on the sidelines during the primary, or should he spend some money trying to run up the score among Republican voters (perhaps portraying Parks as too liberal) and seeking to make some inroads among nonpartisan voters?

Finally, what about turnout? In June 2010 there was a contested campaign at the top of ticket for the GOP nomination for governor and no top-of-the-ticket action among Democrats. This year, with the withdrawal of Rick Santorum from the GOP presidential primary, there will be no top-of-the-ticket contest to favor either party. That will likely make a difference; perhaps with no Meg Whitman spending $40 million to drive Republican turnout, the spread between Republican and Democratic turnout will not be as severe this year.

As the spreadsheet shows, a small increase in Democratic turnout or a small decrease in Republican turnout can make a very big difference.

To try different scenarios, download this spreadsheet and edit it in Excel by clicking here »