Michael Bloomberg, Sarah Palin and the Koch brothers will not appear on any ballots this year. But in some of the biggest midterm races in the country, you're going to hear a lot more about them between now and November 4.

It's all part of a strategy candidates and interests groups in both political parties are using: Find bogeymen (and women), then relentlessly tie them to opposing candidates.

The National Rifle Association announced Tuesday that it is kicking off a multimillion-dollar campaign that will extend beyond November to tar the reputation of Michael Bloomberg, perhaps the country's most powerful gun control activist. The NRA launched a TV ad that slams Bloomberg not only on his gun policies, but also over his push as mayor of New York City to ban large sugary beverages.

In other words, they want to give you lots of reasons to dislike the guy.

The NRA is aiming at Bloomberg, not specific candidates, the organization says. But the ad campaign -- which includes both online and television components -- just happens to be headed for some of the biggest battleground states of the 2014 election, like Colorado, North Carolina and Kentucky.

Personality often complements policy in campaigns. The NRA is wagering that by casting Bloomberg as a wealthy Northeastern elitist who wants to tell people how much soda they should have, they'll arouse more anger about his gun control agenda.

It's the same thing Democrats have been trying to do with the billionaire industrialist Koch brothers, Charles and David. The Kochs are backing conservatives candidates and causes through secretive groups like Americans for Prosperity. If Harry Reid has his way, the secret will be out -- everywhere.

Reid, the Senate majority leader, has led a campaign to raise the profile of the Kochs, casting them as enemies of working class voters in speeches on the Senate floor. Democratic groups and candidates have followed his lead, painting the brothers as villains on the campaign trail. Sen. Mark Begich (D-Alaska), who easily won his primary Tuesday and faces a difficult general election campaign, went after the Kochs in his very first TV ad earlier this year.

Begich's allies, meanwhile, hope to turn Alaska's most famous former governor into an anchor on his opponent, former attorney general Dan Sullivan (R). Shortly after Sullivan won his primary, the Democratic Senatorial Campaign Committee accused Sullivan of "carrying water" for Sarah Palin, who was governor when he was attorney general.

It was the second race in as many days in which the DSCC sought to inject Palin in the the conversation. The committee on Tuesday released an ad tying Iowa Republican Senate nominee Joni Ernst to Palin, calling both "too extreme." Palin backed Ernst in the primary.

Then there's the most obvious 2014 bogeyman: President Obama. With his approval rating hovering in the low 40s, Republicans have been running attack ad after attack ad linking Democrats to the unpopular president.

Which bogeyman will startle voters -- and which will leave them yawning?

For starters, there is little evidence to suggest that behind-the-scenes financiers will be taken heavily into consideration by voters. Republicans tried that tack with George Soros last decade. It didn't work. Even in a post-financial crisis world more hostile to most things Wall Street, there's little fresh data to suggest it will work any better now -- or that the public has suddenly started caring about campaign finance issues in general.

This bodes well for Republicans when it comes to the Kochs -- who, polling suggests, are unknown to most people. To a lesser extent, it bodes well for pro-gun control Democrats and Bloomberg. Why a lesser extent? Because Bloomberg is a much more recognizable political figure than the Kochs. He does many more interviews. He was an elected official. It's simply easier for groups to cement his image in voters' minds.

The strategy has a better chance of working with someone like Palin -- especially in Alaska, where she's not terribly popular. And Republicans will no doubt spend millions trying to use Obama -- the most visible politician in America -- as bogeyman No. 1 in dozens of races, so long as his approval stays low.

Just because you've run your last campaign doesn't mean the political world is done running against you.