While candidates travel state to state collecting donations and giving speeches, Congress is still in session.
Some make a point of getting back to Washington to vote. Senator Rand Paul has only missed two votes since the beginning of the year and Senator Bernie Sanders just six, but other candidates haven't been quite as focused on their elected office.
Senator Marco Rubio has played hooky the most, missing 73 votes. Senators Ted Cruz and Lindsey Graham aren't far behind with 59 and 58 missed votes respectively. That means all three senators have missed more than one out of every five votes since the beginning of the year and Rubio has missed more than one in four.
However, this isn't just a Republican problem. During the 2008 campaign, Democrats also had trouble tending to their day jobs while running for president. In 2007, then-Senator Barack Obama missed nearly 80 percent of votes in September and October, according to a November 2007 report from CNN. Then-Senator Hillary Clinton missed 63 percent of senate votes during that same period.
The president's absentee record from his days in the Senate shows that missing votes does not appear to be a deal breaker with voters. So Rubio may be wise to prioritize fundraising and campaigning.