The Kentucky Republican is unabashedly clearing a path to seek the 2016 GOP presidential nomination, with a series of early voting state visits, a beefed-up political operation and a deliberate plan to appeal to mainstream voters and raise his national profile.
Paul's road is far from easy, given the galaxy of Republican stars considering running for the party's presidential nod - former Florida Gov. Jeb Bush, Florida Sen. Marco Rubio, 2012 vice presidential candidate Paul Ryan and more. But Paul enjoys tea party backing and a network of supporters from father Ron Paul's back-to-back White House bids.
Among the challenges facing the 50-year-old freshman senator: He must convince Republican mainstream voters that he is more than a tea party champion or simply heir to his libertarian dad's ideals. And he has begun making the case that he could bridge the divide between Republican voters and those who overwhelmingly choose Democrats. At historically black Howard University last month, Paul said the GOP needs to appeal to black voters and other minorities. And he's adopted a more welcoming tone toward Hispanics by pledging to "find a place" for working immigrants.
Paul's presidential coming-out begins on Friday in early-voting Iowa.
The senator is billed as the main speaker at the state Republican Party's annual spring fundraising event - called the Lincoln Day Dinner - in Cedar Rapids. He'll also address the Iowa Federation of Republican women and meet with Johnson County Republicans during the two-day trip.
Ten days later, Paul is slated to deliver the keynote address at a similar event for the New Hampshire GOP - the Liberty Dinner - in that important early primary state. He'll cap May's busy travel schedule with a speech at the Ronald Reagan Presidential Library in California on May 31.
The senator also has plans to attend a June 28 fundraiser for Republicans in South Carolina, another early-primary state in presidential nominating campaigns. Paul made his interest in the state known last week when, in a break with national Republicans, he supported scandal-scarred former Gov. Mark Sanford in an ultimately successful bid to return to the U.S. House.
He also plans to return to Iowa in June to meet with evangelical pastors who tend to influence a loyal segment of the state's GOP caucus-goers.
From his schedule and statements, Paul is unlike most prospective candidates, who play coy about their intentions. Paul and his team are being upfront about it - with the same kind of candor that has attracted a huge tea party following.
"We're considering it," Paul told Washington reporters last month. Yet he added: "We won't make a decision before 2014."
Aides say that timeline still stands but that Paul has begun on a path to a White House campaign.
"You can be doing things that have a purpose whether or not you make that other decision," said adviser Doug Stafford. "They still make you a national leader."
Paul's staffing choices also point to a presidential run.
Stafford recently left his position as the senator's chief of staff to become executive director of the political action committee - Rand PAC - charged with starting to put the pieces in place for a possible national campaign.
Among the most important things Paul has done is a carefully built alliance with Senate GOP leader Mitch McConnell, also of Kentucky, after beating McConnell's hand-picked candidate for Senate in 2010. The resulting overlap of top political staff suggests a level of trust between the two.
The partnership has helped Paul, a onetime outsider, gain entrance with the Republican establishment while keeping the tea party's anti-establishment element off McConnell's back. And while it's not clear whether McConnell would endorse Paul in a 2016 presidential field, McConnell would have no qualms publicly lauding Paul's seriousness as a candidate, McConnell aides said.
The prospects of a Paul candidacy became a hotter topic in political circles after the senator's high-profile, 13-hour filibuster in March over the Obama administration's use of unmanned military aircraft to target terrorist suspects. At the time, Paul said he opposed using drones on American soil, but then made some libertarians flinch by adding later that he didn't care if a police officer or a drone killed an armed robber. He said that using technology to stop any imminent threat was acceptable.
According to a Gallup poll taken in March, most people don't think drones should be used in the U.S., an opinion held across party lines.
Paul's stepped-up national presence is not unique among his potential presidential rivals. Bush has said he's open to a run for the White House. Similarly, Rubio has staked out a visible role in bipartisan immigration legislation that is beginning to move through Congress.
But Paul has some advantages in early voting states. His father's support network is one.
In Iowa, his father's former campaign aides hold senior positions in the state Republican Party committee. Paul also is close to former South Carolina Sen. Jim DeMint, a hero in the tea party movement who has a deep network in that state.
In New Hampshire, where his father finished second in the 2012 primary, Paul's fiscal hawkishness could play well with the state's independent voters.
Even so, Paul is bound to face tough scrutiny from key Republican constituencies for statements and positions that challenge GOP orthodoxy on social and national security policy.
He raised eyebrows when he said recently that fighting gay marriage in Congress is a losing proposition, based on the nation's increasing acceptance of same-sex unions, and that he didn't "mind if the government tries to be neutral on the issue." Paul, who opposes same-sex marriage, has said the issue is better argued at the state level.
But aides acknowledge that some devout evangelical conservatives in early primary states such as Iowa and South Carolina won't accept Paul's argument.
Among those who do - for now, at least - is Iowa Republican National Committee member Tamara Scott, one of Iowa's leading Christian conservatives. She sees it this way: "He's trying to strategize where we can keep marriage as God designed."
Another recent Paul remark - that Republicans have been too willing to deploy military forces around the globe - could sting him in South Carolina, a state with many veterans and active-duty troops.
Paul isn't nearly as rigid on international affairs as his father, whose opposition to deploying the military to keep Iran from acquiring nuclear weapons hurt him in Iowa during last year's caucuses. But both talk of a desire to reduce federal spending on foreign aid and a less aggressive role for the U.S. military.