1. If Republicans don't gain the six seats they need to control the Senate in 2015, it's not because it didn't have quality candidates. Republicans were much more successful in navigating Senate primaries than they have been in recent years. In Georgia, controversial Reps. Paul Broun and Phil Gingrey didn't even make the GOP runoff. In North Carolina, Thom Tillis easily outpaced conservative and irksome competition to his right. No Republican senator fell in a primary for the first time since 2008. After being stung hard in 2010 and 2012 by flawed nominees who cost the party winnable seats, Republicans escaped the primaries in good shape. Part of the success was due to better — and earlier — preparation by incumbents. Part of it was GOP groups Crossroads and the Chamber of Commerce playing in primaries on behalf of electable candidates.

2. Being an incumbent is still powerful, even though people are fed up with Congress. When Rep. John Tierney, D-Mass., was defeated by his primary challenger on Tuesday, he joined the ranks of just three other members of Congress who were ousted this year: Eric Cantor, Kerry Bentivolio and Ralph Hall. No senators were defeated. Polls have shown Americans expressing a deep, sometimes historic, dissatisfaction with Congress and even their own elected representatives. But that didn't result in a "throw the bums out" kind of primary season.

3. There are signs that turnout could be very, very low in November. Voter turnout in statewide primaries was down 18 percent from 2010 in the first 25 states to vote this year, according a study by the Center for the Study of the American Electorate.

4. The Tea Party will need to rethink its strategy in future elections. The primary season wasn't devoid of Tea Party wins, but it was full of more disappointing losses than in the past. National Tea Party groups poured big money into unseating Senate Minority Leader Mitch McConnell, R-Ky., and Sen. Thad Cochran, R-Miss. Both senators won. Those who seemed ripe for strong Tea Party challenges, like Sens. Lamar Alexander, R-Tenn., drew only gadfly competition. The GOP establishment was more aggressive than in 2010 and 2012. Now the Tea Party must respond.

5. The most important person in the battle for the Senate may be a candidate who didn't have to go through a primary. We're talking about Greg Orman, the wild card independent candidate in Kansas who won't say which party he would caucus with. Imagine a scenario in which Republicans gain exactly six seats, but Orman unseats Republican Sen. Pat Roberts. The independent would become the most sought-after man in Washington. The fact that the Democratic nominee dropped out suggests there is a chance Orman would rejoin Democrats.

Washington Post