On the eve of the New York primary, where he's expected to dominate, Donald Trump reorganized his top campaign staff, letting go longtime loyal aides in favor of seasoned political operatives.  The move is not unexpected, given the lack of experience by his old staff on national campaigns.

Trump's national field director Stuart Jolly resigned on Monday – an amicable parting, according to Jolly. 

Washington Post:

Jolly -- whose resignation was first reported by Politico -- said in an interview that he recently learned that he would no longer report to Lewandowski and would instead report to newly hired national political director Rick Wiley, who previously managed Wisconsin Gov. Scott Walker's campaign.

"That wasn't going to happen," Jolly said of the change in leadership. "I just decided not to go that route and let the new team have a shot at it. We have a great group of folks in place on the ground, and they're kicking butt and doing great work. We had 22 successful campaigns -- our guys on the ground just did a fantastic job."

Jolly made clear in his letter to Trump that his resignation is not because of the candidate, Lewandowski or the field staff.

"It was time for me to go," Jolly said in an interview. "I would rather go out on top than, you know, go after a loss or something. I went out on my own -- I wasn't pushed out or forced out. I wasn't asked to leave, quite the opposite. It's been a good ride. I would do it all again."

On Monday Trump also hired one of the GOP's top legal minds on convention and delegate matters. William McGinley, a veteran Republican elections attorney, will advise the campaign on the arcane process of selecting delegates and the convention rules process, a person familiar with the move said late Monday. News of the hire was first reported by Politico.

McGinley is a partner at Jones Day, the same firm that employs Don McGahn, Trump's top campaign attorney. While better known in Washington for representing members of Congress facing ethics issues, he advised the 2012 GOP convention rules committee and once advised the Republican National Committee and National Republican Senatorial Committee on ethics, ballot and campaign finance issues. His background will lend much-needed knowledge to a campaign still struggling to master the trickiest elements of presidential politics.

The recent performance of Trump's staffers at state conventions placed in stark relief the inexperience and lack of knowledge by Trump's staff of the arcane rules governing delegate selection.  The new team should help the campaign immeasurably in that respect.

Trump has also formalized lines of communication, which will make the campaign more nimble when responding to trouble.  Perhaps most significantly, Trump's hire of McGinley shows that he's now serious about fighting for every delegate and winning the battles on the convention floor that could lead to victory on the first ballot.

There is nothing unusual in staff shakeups, even for a frontrunner.  As the campaign suffers growing pains, moving from a state-to-state operation to a national organization, experience counts.  The old hands Trump has hired will steady the ship and give him the best chance possible to win.