Tom Bevan of RealClearPolitics has an interesting take on the five biggest mistakes made in the presidential campaign up until now. One was Fred Thompson's decision not to participate in the first GOP debate in NH, for which Granite State voters appear to be punishing him. A second was Mitt Romney's failure to do his Big Religion Speech earlier in the cycle, making it now look like an act of desperation. A third was Hillary Clinton's refusal to consider skipping Iowa, where she's now in a difficult struggle that could destroy her national lead.

Bevan attributes a fourth and fifth big mistake to a single candidate, John McCain, for his notably unsuccessful "front-runner" strategy early in the race, and for his poor handling of the immigration issue.

20-20 hindsight is often easy, but now that voters are on the brink of finally weighing in, it is interesting to think about how the race might have been reshaped.