Of course both candidates are moving toward the center. They're learning from Barry Goldwater's experience in '64, and George McGovern's eight years later. Both won their respective nominations through fervent support of a right-of-center (Goldwater) and left-of-center (McGovern) faction in their parties. And both lost by huge margins in the general election because they failed to reach out to the middle--they just preached to the choir.
Here is a good opinion article about reaching out toward the middle:
The Audacity of Listening Here is an excerpt:
Think back. Why, exactly, did you prefer Obama over Hillary Clinton in the first place? Their policies were almost identical — except his health care proposal was more conservative. You liked Barack because you thought he could get us past the old brain-dead politics, right? He talked — and talked and talked — about how there were going to be no more red states and blue states, how he was going to bring Americans together, including Republicans and Democrats.
Exactly where did everybody think this gathering was going to take place? Left field?
When an extremely intelligent politician tells you over and over and over that he is tired of the take-no-prisoners politics of the last several decades, that he is going to get things done and build a “new consensus,” he is trying to explain that he is all about compromise. Even if he says it in that great Baracky way.
