More than 65 million viewers watched the second presidential debate between Mitt Romney and President Obama, according to Nielsen Ratings on Wednesday. 

That's about a 2 million viewer drop from the first debate, which had 67.2 million watchers.

The 65.6 million viewership on Tuesday is slightly higher, by 2.4 million viewers, than the second debate in 2008 between Obama and Sen. John McCainJohn Sidney McCainGOP strategist donates to Alabama Democrat Meghan McCain knocks Bannon: 'Who the hell are you' to criticize Romney? Dems demand Tillerson end State hiring freeze, consult with Congress MORE (R-Ariz.). Viewership was also higher than the vice presidential debate, which took place about a week earlier. That debate had a viewership of 51.4 million viewers.

The second showdown was a contentious town-hall debate that featured sharp attacks between Obama and Romney. The first debate, where Obama gave a lackluster performance, was on domestic issues.

The final debate between Obama and Romney will be on foreign policy and is set to take place at Lynn University in Boca Raton, Fla., on Oct. 22.

In 2008, the second debate between Obama and McCain was the most highly rated of their three outings, followed by the third debate (on domestic issues) and then the first one (on foreign policy issues). It was also a town-hall-style debate.