If Trump pulls the Kavanaugh nomination it will be the biggest Democrat triumph since 2012 and they will scream with joy and exaltation for the next 6 weeks.
Not only will they not thank Trump for any reasonableness on his part, they will barnstorm the country promising to impeach him if they win the House.
Take that to the bank. The only win for Trump out of this is Kavanaugh on the SC. Otherwise he loses.