Actually, they were aware of the threat.

Several framers of the constitution expressed deep concerns about the potential for coordinated non-governmental "factions" taking over government via elections.

Unfortunately, despite going to great efforts to limit power centralization internally, concerns of external centralization were not heeded and there are no limits on the coordination of the US government via non-governmental organizations such as parties.

This might have been a prophesy:

> Without looking forward to an extremity of this kind (which nevertheless ought not to be entirely out of sight) the common and continual mischiefs of the spirit of Party are sufficient to make it the interest and the duty of a wise People to discourage and restrain it.

> It serves always to distract the Public Councils and enfeeble the Public administration. It agitates the Community with ill founded jealousies and false alarms, kindles the animosity of one part against another, foments occasionally riot and insurrection.

> [Omitted here, but at this point he worries that even a foreign country could weaponize a party to take control of the country, via elections.]

> There is an opinion that parties in free countries are useful checks upon the Administration of the Government and serve to keep alive the spirit of Liberty. This within certain limits is probably true, and in Governments of a Monarchical cast Patriotism may look with endulgence, if not with layout, upon the spirit of party. But in those of the popular character, in Governments purely elective, it is a spirit not to be encouraged. From their natural tendency, it is certain there will always be enough of that spirit for every salutary purpose. And there being constant danger of excess, the effort ought to be, by force of public opinion, to mitigate and assuage it. A fire not to be quenched; it demands a uniform vigilance to prevent its bursting into a flame, lest instead of warming it should consume.

-- George Washington [0]

States used to operate independently enough that the same party in different counties and states might have varied views. But today, both parties have become highly centralized and homogenous from local to federal levels. Now intensely centralized themselves, they are well prepared to each compete to centralize government as an extension of a single party.

And given it has become relatively easy to do so, the incentives are now there for parties to treat elections as war, and party control of government as the highest priority policy at all times. Incentives don't mean it has to happen, but ... well we know how that goes.

The winner take all elements, where a party that gains a power edge over the other is in a better position to entrench themselves further, if not permanently, are also in play.

When competition for power devolves into a dichotomy of complete wins or losses, the most powerful decision makers spend their time continually competing, with little attention left for concerns about competent governance or the public's well being.

The current state of the unchecked US party system is the number one problem for the country. As all other problems migrate downstream from it.

The biggest problem isn't "which" party gains control. The problem is that any party could ever obtain majority control in all three branches.

[0] https://www.loc.gov/resource/mgw2.024/?sp=241&st=text

Well it depends : you can easily slip into a "tyranny of the majority" setup where the parties in power don't need to accommodate the needs of the minority. Also if your regime is optimized for solving minor issues, it will have a hard time when there are important ones.

In general, there is no silver bullet, and as Solon (creator of the first constitution in the Antiquity) put it, each country will need a custom regime to fit its specific culture and society.

Macron is still around because France is a presidential regime and he can't be removed.