Both senators have approvals below 50%, which is always something special. For Brownback, this is a 10% drop in approval and a 19% drop in net approval since December.
For Roberts, it's a smaller drop since he's been around 50% for a few months now. He was in the high 50s in February, and his approval dropped to 50% since then.
Brownback's approval among Republicans dropped starkly last month, a 17% net drop, disapproval among Independents rose, while Democrats were unchanged. Conservative and moderate approval held steady, while liberal disapproval drifted down a bit.
If I were guessing, I'd say a lot of this shift comes with the immigration debate, where Brownback has taken a much more moderate position than many other conservatives.
Roberts' approval ought to be more driven by his position on illegal domestic surveillance. He dropped 14% in net approval among Republicans, and held steady among Independents and Democrats. He held largely steady among the different ideological groups.
It's worth noting that there were 6% more liberals and 3% more moderates in the sample, possibly suggesting a shift in the public's identification with different ideologies. Both had a jump in approval in Wichita and dropped in Eastern Kansas.
Pennsylvania's Rick Santorum is the least popular senator, behind scandal plagued Conrad Burns.