"He puts everybody to shame in terms of his endurance," she said.
The Ohio governor says he won't let "people just pound" him with attacks.
The move comes after a disappointing finish in the New Hampshire primary.
Timothy Cama 02/10/16 04:39 PM EST
Two groups are backing Feingold over Sen. Johnson.
"I don't think there's any doubt," said the former White House press secretary.
Julian Hattem 02/10/16 04:19 PM EST
The emails reportedly hit the inboxes of many of Clinton's top aides.
"Bernie Sanders has been largely missing in action," Rep. Hakeem Jeffries said.
Right to Rise USA has now invested more than $10 million in the Palmetto State.
She finished in seventh place in Tuesday's New Hampshire primary with just 4 percent.
"You can't beat Donald coming from the left," Cruz said.