If Bob Menendez wanted to legally get rich while being a senator, he could've just written a more popular book

• Sen. Bob Menendez took bribes of cash, gold, and other luxury items, according to a new indictment.
• But there's a way more legal way to make money as a senator — just write a best-selling book!

Sen. Bob Menendez has been indicted for the second time in 10 years on bribery charges — and the fruits of that alleged bribery are nothing to sniff at.

According to the indictment unsealed on Friday, the New Jersey Democrat and his wife, Nadine, received the following gifts in exchange for enriching a trio of New Jersey businessmen and steering US policy to benefit the government of Egypt:

• A Mercedes-Benz C-300 convertible.
• $566,221 in cash, some of which was "stuffed into envelopes and hidden in clothing."
• Lots of gold bars, some of which weighed an entire kilogram.
• Other items including mortgage payments, an exercise machines, a recliner, and an air purifier.

The problem for Menendez, of course, is that bribery is illegal. He has denied the validity of the charges, arguing in a statement that "those behind this campaign simply cannot accept that a first-generation Latino American from humble beginnings could rise to be a US senator."

But there's a totally legal way to make extra money — sometimes way more money than the $174,000 salary — as a sitting member of Congress.

It's called writing a book.

Six of Menendez's colleagues more than doubled their salaries via book royalties and advances. Democratic Sen. Raphael Warnock of Georgia reported earning more than $650,000 — even going on a mini book tour as he fought for his political life against Republican Herschel Walker.

Even Sen. Bernie Sanders, an avowed democratic socialist, managed to double his income by writing a book railing against capitalism.

The other totally legal way to make some extra money as a member of Congress is by trading stocks, though doing so might lead to accusations of insider trading.

Still, insider trading by members of Congress is fairly difficult to prove, and the enforcement for violating disclosure laws is pretty lax, so that probably still would've been a better route than allegedly accepting bribes.

Interestingly enough, Menendez has written a book — "Growing American Roots: Why Our Nation Will Thrive as Our Largest Minority Flourishes" — in which he offers a "step-by-step plan" in which America's future "will be made brighter and more successful" by the "burgeoning influence of the Hispanic population."

The New Jersey senator once presented Eva Longoria with a copy of the book at a 2009 Capitol Hill press conference about establishing the National Museum of the American Latino. The "Desperate Housewives" actress even contributed a jacket review for the book.

According to Menendez's financial disclosures, he signed a contract in 2009 to receive at least $50,000 from the book, splitting the proceeds with his co-author, Peter Eisner. He has not, however, disclosed received any royalty payments in the years since then.

That would seem to indicate that Menendez's book wasn't exactly a cash cow for him.

Perhaps if he had run for president, as many of the top book-sellers in the Senate have, he could've written another book and made more money, the legal way.