Not only that, for the 2012 election cycle, there were 117 polls from Ohio, from January 19, 2012 through election day.
You can see all 117 of those polls here:
Google Sheets - create and edit spreadsheets online for free.
Also in 2011:
Statistikhengst s ELECTORAL POLITICS - 2013 and beyond Statewide polling data through 11 16 2011 - NH through WI
From December 2010 to end of November 2011, there were also 12 Ohio polls, Obama vs. Romney.
So, that makes a total of
129 polls for the Buckeye state.
For any given month up to End of October, Obama's aggregate (polling average) in Ohio was always between +3 and +4.
At the very end, his aggregate landed at +3.
One election night, Obama won Ohio by +3 (+2.97, to be exact).
You can take the polling starting in the spring of 2012 and drop the needle anywhere and compare a 2 week time-frame or a 4 week timeframe from that point and the average is between +3 and +4 for Obama. His polling in this state was far more consistent that the polling for Bill Clinton (92, 96), for Gore vs. Bush (2000), for Bush vs. Kerry (2004) and even more consistent that his own battle against John McCain in 2008.
The very proof that the Romney team took these statistics seriously is that they suddenly shifted attention to Pennsylvania, realizing that Obama had a slim but consistent lock on Ohio. And I reported on these statistics all through 2012 and especially in the last 7 weeks, where I published nightly BATTLEGROUND REPORTS for 42 nights straight. Here is the first one:
Statistikhengst s ELECTORAL POLITICS - 2013 and beyond Battleground Report 09 25 2012 - T-minus 42 days
Ohio, Florida and Virginia were the three most polled states of the 2012 cycle and Ohio was by far the most consistent state in the Union in terms of polling performance. In aggregate polling, Romney never got ahead of Obama, not even once.
And as goes Ohio, so goes the nation.
Oh, and just for fun, a complete analysis of ALL end polls for all states, by pollster:
Statistikhengst s ELECTORAL POLITICS - 2013 and beyond The moment of truth how did the pollsters do