Because if she follows the Rubio model of "Tea Party Vs. Old Guard" and gains a seat in a conservative state she can stay in Virginia/DC 360 days of the year and still run unopposed for the next 5 terms. In VA she'd have a fight on her hands every election.
Yea, the cowardly out. Actually, I like Liz Cheney. She could handle either Warner or Eyebrows. But I AM getting mighty sick of these political dynasties, whether D or R.