Claire McCaskill has been in the US Senate since 2007. Obama assumed office in 2009. All through 2009 and 2010, both chambers of Congress and the White House were controlled by Democrats. McCaskill did NOTHING to try and end or reform the Patriot Act during that time. The US House went Republican in 2011, but the Senate remained in Democratic control until 2015. She has had 8 full years in a majority position with a Democratic President to offer any kind of reform package for domestic surveillance and she did not. The fact that her own party was in control of both chambers of Congress and the White House after her first couple years, and then she spent another 6 years in a Senate majority with a Democratic President is entirely relevant.
Like it or not, politics is done by parties and majorities. She is in the Democratic Party, and she has been in the majority for a very long time. The criticism is quite appropriate.
NOW that Republicans are in the majority, it makes more sense to be critical of Republicans.
It was silly to criticize Senate Republicans for getting nothing done while Harry Reid was in charge. Of course they got nothing done: Harry Reid was in charge. Now the shoe is on the other foot, and we await with bated breath what wonderful things the Republicans will (fail to) do.
The observation that Claire is a Democrat who was in a Democratic majority, and failed to do anything of what she is criticizing Rand Paul for actually doing, is a valid observation. That's not really partisanship as much as it is simple recognition of political reality.