Is past tense correct here?
What is the difference between the following:
Didn't you know there was an election today.
Didn't you know there is an election today.
Isn't the second one ungrammatical?
In the first sentence the intent of the asker is not to get an answer from you, but rather to provide you with a piece of information.
What the asker actually saying is: "There was a tunderstorm today."
The second sentence makes sense if you reword it as follow: "Didn't you know there is a thunderstorm now?"
In this case the asker actually say: "There is a thunderstorm now."