I suppose witness tampering will be added to the articles of impeachment. Given it was live and online and she said she felt threatened at that time, speaking to Congress as it happened, it’s rather hard to deny. In fact, you’d have to be delusional to deny it.
The only defense would be that Trump is too ignorant to understand what he was doing. Which isn’t a great defense, as has often been said, “ignorance of the law is no excuse!”
And not exactly a great look going into an election. Though I doubt that would make any difference to the 40%.