Sen. Rand Paul is set to make official a presidential bid that has long been expected, a senior adviser to the Kentucky Republican said Tuesday, pointing to April 7 as the kickoff date.

Paul’s political team has invited backers to a midday event in downtown Louisville, Kentucky. The tea party hero was then set to visit the early nominating states of Iowa, New Hampshire, South Carolina and Nevada — familiar destinations for him as has prepared for the formal entry into the race.

The adviser demanded anonymity to speak ahead of Paul’s public announcement. The adviser adds that Paul could still pull the plug on a campaign, although that is not expected to happen.

A spokesman for Paul, Sergio Gor, declined to comment.

Paul would be among the first of the potential 2016 contenders to officially enter the race for the GOP nomination. He begins his presidential campaign as a familiar face among tea party- and libertarian-leaning voters, but also something of an odd-man-out among the establishment-focused corner of the GOP.

Paul’s challenge will be to build backers among his natural base of support in the party while reassuring others that his views on topics such as foreign policy are not too far outside the mainstream. His critics — Republicans and Democrats alike — already have collected dozens of examples of Paul’s rhetoric that they plan to use against him.

Paul will also have to cobble together the tens of millions in campaign donations that the nomination will cost.

Paul has proved a formidable fundraiser, especially from low-dollar and younger donors who back his limited-government pitch. But Wall Street-style Republicans have been rushing to sign up with other likely candidates such as former Florida Gov. Jeb Bush, Wisconsin Gov. Scott Walker and Sen. Marco Rubio of Florida.

In an interview Tuesday with The Associated Press, Rubio said he could “potentially” announce a bid in April but that he had not settled on a specific date.

“If you’re going to run for president, you need sufficient time to raise the money and build the organization to be successful,” Rubio said, adding that his decision would come “soon.”

Paul’s timing coincides with both the fundraising and political calendars. The second quarter of political fundraising opens on April 1, and several candidates are looking at formally joining the campaign soon after to take full advantage of the three-month window.

Candidates who join the campaign any time in April, May and June will have to report their fundraising tallies by July 15 and it will be one of the first benchmarks for a campaign’s success. The sooner candidates declare in April, the more days they will have to collect checks.

Easter this year, however, is April 5 and many voters will not be paying attention to politics during that weekend.

Paul’s day job in the Senate is also a factor in the timing. Senators are scheduled to be away from Washington that first week of April, giving Paul a chance to make swings through the early nominating states without missing votes.

Paul’s potential rivals in the Senate, such as Rubio and Ted Cruz of Texas, face similar scheduling pressures. By telegraphing their pick of Tuesday, April 7, at Louisville’s Galt House hotel, Paul’s team was hoping the others would have the courtesy to schedule their likely announcements on other dates.

Paul’s team has planned a New Hampshire visit the day after the Louisville launch. He plans a visit to South Carolina on April 9, Iowa on April 10 and Nevada on April 11.

Details of the kick-off event were first reported by The Lexington Herald-Leader.

(AP)