Maybe it's mostly a result of Dems taking over leadership of Congress.
Very few Dems seem happy about current troops strength in Iraq, some want severely lessen the number [run away], others [or even the same ones] want to dramatically increase the size.

Obviously adding 50,000 isn't a huge increase but it could be considered a "start in the right direction". Or maybe they will actually increase it by 100,000 when they say they are increasing it by 50,000.

With an Iraqi security force of more than 300,000 and with the Iraqi security forces being increasingly in charge of various zones in Iraq, it doesn't make much miltary sense to increase US troops levels.

But also of course it doesn't make much sense to tell your enemies the exact number of troops you have in a particular area. In other words the 130,000 may roughly be the number of troops in Iraq, but it doesn't represent the number in the region involved in some way with Iraq. You could have a situation where you increase the number *in* Iraq yet at same time decrease the number in the entire area *for* Iraq [and you could instead be surging in Afghanistan or have some other purpose]. Deception and misdirection are always a part of war.

And with the above in mind, maybe the dems simply want to change what is being said rather make any changes in what is actually being done.