I'm not sure if I've asked this before, but why is Washington's state legislature so close when overall the state is pretty heavily Democratic in other races, particularly statewide? Democrats have lost seats in the State House in every election since 2008, which is just something I find a bit odd given how Democratic the state is overall and their relatively large turnout elections. Democrats only have a 1-seat majority now and if they don't buck the current 8-year trend, they'll effectively lose control of the State House and thus the entire legislature.
I would say the PA legislature is more lean R than likely. The R majorities aren't that big, and they have every reason to be unpopular.
The GOP's legislature majorities are the largest they have had since the 50s. Democrats need a net gain of 18 seats in the State House to carve out a bare majority. Neither party has achieved that many gains in one election in over a generation. To top it off, the state districts are thoroughly gerrymandered by Republicans to hold a majority, so that makes me think it would take a rather large wave to sweep them out of power.
However, based on voting trends of age groups in PA since the late 90s, I'd say Pennsylvania is trending more Democratic and as such as happened in other states, that effect could manifest itself rather abruptly with GOP seat losses if the trend does indeed continue.
