Rand Paul seems to be crossing over to the mainstream — or maybe it's the other way around. When Kentucky's junior senator arrived in Washington just over two years ago, he seemed destined to inhabit the role of perpetual outlier. But now, he's in the mix on just about everything that is happening, and talked about as a credible Republican presidential contender in 2016.

Paul is also aggressively trying to forge at least a cordial relationship with GOP establishment interests that have been suspicious of him or even outright hostile in the past.

"He is a work in progress," said one well-known Republican who recently met with Paul, and did not want to be identified, because public disclosure of that fact would not be of benefit to either of them.