This article originally appeared on Slate.
Will this be a wave election? In these uncertain times, when we use a weather metaphor it should be clear. You're either wet or you're not. But it's not clear, because we're using the wrong metaphor. The Republican tide is coming in this election -- the GOP will pick up seats in the House and Senate -- but the question remains: How big will the wave be? Will it be a gentle lapping that excites the ankles or will it knock you back and part your hair?
This isn't just a matter of abstract classification. Whether a party's victory is declared a wave or not sets the conditions for the conversation when that party turns to governing. It is a shorthand expression about the power of one party's ideas, or at least a signal of public revulsion about the ideas of the losing party. It matters in the public debate; if the GOP does well enough, Republicans will point to that strong result as a ratification of whatever they're pushing (even if they didn't mention those ideas during the actual campaign). If Republicans win in states where Democrats traditionally do well, there will be less introspection about party positions. If they are only victorious in the places where they were expected to win, the internal spats over hot-button issues or whether candidates were too moderate (and not proud conservatives) will recommence.
Political scientists would warn us about drawing conclusions about the fundamentals of politics based on a handful of off-year election victories--and they'd be right. But one thing is certain: The outcome of these races and how they are characterized will provide the language for strategists, politicians, and party fundraisers in the conversations to come. It is in that context that we offer a preliminary classification scheme for the results in the Senate races. In other words, how to read a wave:
Undertow: The GOP doesn't take the Senate. Republicans have everything going for them this cycle. They recruited good candidates, the president is unpopular, and they have plenty of money to compete. If Republicans do not win the six seats needed to take control of the Senate, it will be because they lost at least one state Republicans regularly win in presidential elections. Not only would they have failed to take advantage of Obama's dismal approval ratings, they would have failed to win on their home turf.
Nature's Course: Victories in the six states Mitt Romney won by double-digits. If Republicans win in Louisiana, Alaska, Arkansas, Montana, West Virginia, and South Dakota that's great for the party, and it would give the Republicans control of the Senate, assuming they don't lose in any states Republicans currently hold. Simply winning control of the Senate would give the Republican brand a good push. A lot of voters would equate winning the big prize with a national ratification of GOP ideas. But for people in the trenches, such a victory would only be meeting expectations. Historically, six seats is about the number of seats a president's party loses in the sixth year of a presidency. This result would also represent the new norm for Senate elections, where the trend has been that voters elect senators from the same party as the person for whom they cast their presidential ballot. As a matter of policy the verdict it would render would be that Republican voters agree with Republican policies.
Don't move the beach towel: Republicans win the Romney Red Six and hold Georgia. David Perdue, the Republican candidate in Georgia, has had some stumbles. The former business executive has defended his support of outsourcing in a state that has the second highest unemployment rate in the country. If Republicans win, it will be a sign the party is strong enough to save even bad candidates in a state where shifting demographics have given Democrats a shot. Georgia was the state in which Romney received his second smallest margin of victory after North Carolina.
A moat for your sand castle: A Republican victory in Iowa. This is the spiritual homeland of the Obama movement. The president won the Iowa caucus in 2008 and then captured the state in the general election twice. The Democratic ground game there is robust. But Democratic Senate pick Bruce Braley has drawn mixed reviews as a candidate and had what may be the gaffe of the season, when a video surfaced of him insulting the state's senior senator as merely a farmer to an audience of Texas lawyers he was asking for campaign donations. Republican candidate Joni Ernst has run a disciplined campaign, but she has been trying to downplay her conservative roots to make as few waves as possible. Nothing about the race suggests a grand victory for Republican ideas.
Bringing in driftwood: Winning North Carolina. Barack Obama won in North Carolina in 2008, and Tar Heel country was once considered the kind of modern southern state where the Democratic coalition was on the rise. A GOP win would be the second consecutive victory in the state after Romney's win in 2012. Knocking off an incumbent isn't easy, and Republicans will be able to claim that state Rep. Thom Tillis wasn't hurt by the conservative policies he enacted as speaker of the House--policies Democratic Sen. Kay Hagan talked about relentlessly. Message: You can govern like a conservative and survive in a purple state.
Goodbye sand castle: Winning in Colorado. Barack Obama carried the state twice, and Democrats paid particular attention to the ground game there. They also made it ground zero for their appeal to female voters. If the Republican candidate Corey Gardner wins, it will suggest that well-worn Democratic play may no longer be enough.
Suitable for Body Surfing: If Republicans win in New Hampshire, Iowa, Colorado, and North Carolina. Taking four purple states, most of which Obama carried twice, would allow Republicans to say that they have a message that can win almost anywhere. It would also represent bragging rights in Iowa and New Hampshire--two primary states that tend to get more press coverage than the others. For the next two years, commentators and reporters would reference those Republican victories whenever they ran stories on the presidential jockeying.
The Senate races aren't the only factors that will determine the post-election national landscape for Republicans. The gubernatorial races may, in fact, send equal or greater political shockwaves through the political class. If Govs. Scott Walker and Sam Brownback survive, their names will be repeated by conservatives who argue that you can govern as a conservative and prosper politically. If they lose, they will be cautionary tales as the GOP tries to fashion a message to build support for their next presidential candidate's platform. Every tide contains a ripple of the next big wave.