Campaigns are important, but that does not mean they are decisive. The reason is that the two sides usually neutralize the other – both sides tend to be equally well-funded, their campaign strategists, media mavens, and other specialists tend to be equally skillful, and so on. Thus, their net effect tends to be pretty minimal.
Accordingly, what we are usually left with his the following axiom: A president usually pulls in a vote share roughly equal to his job approval rating.
This is not always the case – for instance, the George McGovern campaign in 1972 was such a disaster that Richard Nixon ended up winning a larger share of the vote than his approval rating would have suggested. Similarly, Jimmy Carter in 1980 had seen major defections among Democrats in terms of his job approval, but many of them voted for him anyway because Ronald Reagan and John Anderson were simply not acceptable choices. In most instances, though, this axiom holds true. Both 1972 and 1980, after all, saw the collapse of the Democratic coalition, something we are not going to see this time.
Where does that leave Obama at the moment?
After the back-to-back debacles of 1980 and 1984, the Democratic party essentially rebuilt its core coalition. Since 1988 the party has not fallen below 46 percent of the two party vote, either in the presidential contest or the national House race. That looks to be the core Democratic base of support in this country.
If we go by his job approval, this is roughly all President Obama is holding at the moment. He pulls in a little bit more in most polls most of the time, but not very much. The most recent read from the RealClearPolitics average of polls has him at 46.8 percent approval. (And the bulk of those polls are either polls of adults or registered voters, which tend to be more favorable to Democrats than the actual electorate.)