I've researched this subject prior to making an ocean front condo down
payment in Mexico. This reasearch was mainly though the book "Mexico
Magico" by German Estrada Navarro.  However, I recently herd that
there may be a change in Mexico's ruling party toward with a push from
the liberal side which if successful could effect the integrity of the
Escritura (Deed of Trust) as it relates to foreign ownership. Is this
a likely supposition?  Doesn't the NAFTA agreement between our
government protect U.S. owners?

This is a personal opinion. I am not an attorney, and not an expert on
Mexican law of escrituras.  However, I have followed such discussions
since 1997 on Mexican/expat forums. And, my Mexican wife of 30 years
and I are building a 3,000 square foot house in the mountains of rural
Puebla, all in her name.

Here is my opinion. As you well know, it is illegal for foreigners to
"own" beach front property in Mexico, period. The law on this is quite
clear and very well known. Ditto for land on the border.

There has been a somewhat successful move to circumvent that law by
paying a bank or some other entity to take ownership of the property
in their own name, under trust for the foreigner who wants the use and
control of that property.

Is there a chance that in the future some legal action could be taken
by the government which would cause those foreigners who are trying to
circumvent the law through loopholes to lose their wonderful beach
front property that they are not supposed to own in the first place? 
Most folks who do know a lot more than I do about Mexico sure think
so.

Note that this is not the same as fully legal foreign ownership of
land where there is no prohibition.  You have used the term escritura
as if it were the same in all cases. If the bank owns that property in
trust, the escritura is in their name, not in yours. If you own a
piece of non-ejido land in rural Puebla in your own name, for example,
the escritura is in your name. Escritura is the word for deed of land,
not just beach front land.

If what I am telling you is a surprise, better do some deep research
before you plunk down your life's savings on a condo.

Different people have different views of life. My view is probably not
going to please you. My view is that anyone who circumvents a
well-known law prohibiting ownership of beach front land by using a
loophole deserves no tears of sympathy if the Mexican government
closes the loophole.  Would I understand the suffering of those who
see their wonderful property confiscated and probably their life
savings gone? Sure, but no tears.

And, there would be no sympathy from the Mexican people who have seen
the foreigners circumventing the well-known law and not only grabbing
up the desirable beachfront land but also driving the price out of
sight. The very intent of the original law was to prevent that land
being grabbed up by wealthy foreigners.