Rabbi Shloime Pollak
How could it be that Yitzchock wanted to give the Brochos to Eisav, a murderer and thief, instead of Yaakov Avinu, the perfect well behaved child??
Rivkah Eimeinu, that saw the greatness in Yaakov, and Eisav's shortcomings, probably conveyed her thought to Yitzchock... yet Yitzchock disagreed??
Rashi tells us, that there was a real concern, that Reuvein might join the forces of Eisav??