“Why did they run for office?”
To destroy what others built.

Omar and AOC ran for office so their hateful and corrupt ideas and plans could stat the final steps in the destruction of the USA as we know it. It won't be immediate or even near term but the ideas are planted and as expected a relatively large number of Democrats have signed on but more importantly, ALL of the Democrat candidates for President accept some or all of the tenants they are spouting.
These ideas will become an integral part of all future Democrat platforms because, IMHO, this set of ideas is what the Democrats truly believe is best for themselves and the country. The order is also key. It helps them much more than the country even if it was good for the country, which it is not.