Why did not the constitutional monarchy survive in France? ( Before Napoleon) Louis XVI.

As in the case of many revolutions, the first is followed
by a second. (The first government of the U.S. for instance, the Articles of
Confederation, was soon replaced as ineffective.) In France, the first revolution
created a Constitutional Monarchy which Louis XVI was forced to accept. The National
Assembly had erred, however, in providing that none of its members would be eligible for
election to the new Legislative Assembly. Those elected to the new assembly, many of
whom were known as Jacobins by reason of their membership in a local political club,
were younger and tended to be more radical. They distrusted monarchy in any form, and
wanted a liberal revolution. They were prone to bombastic speeches and high sounding
oratory during which, among other things, they grouped "despotic monarchs" and "useless
aristocrats" together.

The Assembly declared war on Austria
due to a perceived threat that Francis II would attempt to restore the French Monarchy.
When things went poorly during the war, a radical mob whipped up in patriotic frenzy
accused Louis XVIand Marie Antoinette (who was Austrian) of treason. They were arrested,
imprisoned, and the first Republic of France proclaimed.