Ally says he doubts Los Angeles mayor will decide not to run.
New DSCC head Jon Tester (Mont.) says he won't be successful unless he flips back the Senate.
The GOP senator predicted his Arizona colleague would be "just fine" in a potential primary.
The top-targeted Illinois GOP senator raised $600,000 in the last quarter of 2014.
The controversial Democrat says he has "some very substantial advantages" over others.
Fiscally conservative group "willing to take risk," new president David McIntosh says.
The impressive group of backers could scare off potential GOP primary challengers.
Rep. Kyrsten Sinema launched a leadership PAC, fueling speculation of a statewide run.
The National Senatorial Campaign Committee begins 2015 with more money and less debt than the Democratic Senatorial Campaign Committee, according to numbers provided by NRSC staff.
The NRSC has $2.7 million cash on hand as of the...
After losing nine seats in 2014, the campaign arm starts the 2016 cycle deep in the red.