Republican presidential candidate Donald Trump speaks aboard the aircraft carrier USS Yorktown in Mt. Pleasant, S.C. (AP Photo/Mic Smith, File)

Now we know that the fight between Jeb Bush and Donald Trump has really gotten personal: the lawyers are involved.

Jeb Bush's leadership PAC filed a Federal Election Commission complaint against Donald Trump Wednesday, accusing his campaign of illegally accepting corporate funds by using the Trump Organization's legal counsel to fire off cease-and-desist letters to critics. The PAC received such a letter last week from Alan Garten, general counsel for the Trump Organization, who threatened "immediate legal action" if the group produced ads that attacked the billionaire developer.

But Garten sent the letter to the Right to Rise PAC, a leadership PAC that has made contributions to Republican candidates, instead of to its sister super PAC, Right to Rise USA, which has begun running a television spot hammering Trump and other GOP candidates as unqualified to be commander in chief.

This rookie mistake drew no small amount of derision from Charlie Spies and James E. Tyrrell III, the attorneys for the PAC. In a letter to Garten Wednesday, the lawyers urged him to consult the FEC website "to familiarize yourself about the differences between Leadership PACs and Super PACs." Or, they suggested, he could skim two key federal court decisions in 2010 that paved the way for the creation of super PACs. "They are both very helpful and might clear up some of your confusion," they wrote.

They didn't stop there. Here are a few more choice excerpts:

"We are intrigued (but not surprised) by your continued efforts to silence critics of your client's campaign by employing litigious threats and bullying. Should your client actually be elected Commander-in-Chief, will you be the one writing the cease and desist letters to Vladimir Putin, or will that be handled by outside counsel?...

"If you have time between bankruptcy filings and editing reality show contracts, we urge you to flip through the Supreme Court's decision in New York Times v. Sullivan. If your client is so thin-skinned that he cannot handle his critics' presentation of his own public statements, policies and record to the voting public, and if such communications hurts his feelings, he is welcome to purchase airtime to defend his record. After all, a wall can be built around many things, but not around the First Amendment."

They concluded by noting that federal candidates are not allowed to use corporate resources for campaign purposes, and attached a copy of their FEC complaint alleging that Trump has violated that law.

"Just as your client is attempting to quickly learn the basics of foreign policy, we wish you personally the best in your attempts to learn election law," Spies and Tyrrell concluded.

In a statement, the Trump Organization said it “has vigorously policed Mr. Trump’s brand and business interests for many years. Those rights are not forfeited by virtue of Mr. Trump’s candidacy. Going forward, the company will continue to zealously protect Mr. Trump’s brand and business interests wherever and whenever necessary. This is in no way any form of campaign activity and does not run afoul of federal election laws.”

Read the entire letter below.

Trump-Letter-and-Complaint (PDF)

Trump-Letter-and-Complaint (Text)