Sen. Rand Paul, R-Kentucky, is so serious about running for president, he is actively taking all the steps “that someone in his position should be making,” a GOP source familiar with Paul’s activities told CNN. …

According to the GOP source, Paul has a robust email list with more than two million addresses. He’s been trying to build new relationships among grassroots supporters, by signing letters and sending emails for groups.

He’s also been active in establishing relationships and building an informal finance committee. His team has been working to find donors with big pockets to supplement the small donor component of his and his father’s political operation.

He plans to travel to South Carolina, which holds the first-in-the-nation primary, in the not too distant future, the source said. Paul made “soft promises” to people in other early voting states, including New Hampshire, Iowa and Nevada. The senator, however, doesn’t think those trips are all that critical at this early stage, the source said.