It's tough to be in two places at once. And if history is any guide, all of the senators running for president will frequently forgo floor votes to be on the trail shaking hands and kissing babies.
Sen. Charles E. Grassley, R-Iowa, who hasn’t missed a vote since 1993 and represents a state the candidates will call a second home for many months, said in general the candidates shouldn’t be judged too harshly, or at least no more harshly than others who have attempted the tough journey from the Senate to the White House. "I don’t know that I remember a lot of people like Barack Obama or John McCain — who had a lot of absenteeism — being criticized for it," Grassley said. "I just don’t remember that."
Going to Iowa, meanwhile, is a requirement. Grassley said the key to winning over Iowa voters is to ensure they don’t feel forgotten, and while few Iowans care exactly how many times each candidate visits the Hawkeye State, “You better be active enough that people know you haven’t been skipping Iowa."
One candidate, Sen. Rand Paul, R-Ky., has only missed two votes this year. But the two others, Sens. Ted Cruz, R-Texas, and Marco Rubio, R-Fla., have vote participation percentages of 74.55 percent and 81.82 percent, respectively — the two lowest of Republicans.
But as low as Cruz and Rubio’s voting participation records are — the Senate average is 97.98 percent — there’s still plenty of room to decline.
From 2007 to 2008, all of the Senate's presidential aspirants at that time — Hillary Rodham Clinton, D-N.Y.; Barack Obama, D-Ill.; John McCain, R-Ariz.; and Joseph R. Biden Jr., D-Del. — had the lowest voting participation percentages next to then-Sen. Tim Johnson, D-S.D., who managed to vote about half of the time while recovering from a nearly fatal brain hemorrhage.
During that time period, the Senate average was 94.63 percent, with McCain at 36.23 percent, Obama at 53.74 percent, Biden at 68.19 percent and Clinton at 68.49 percent.
Senate Republicans outnumber Democrats 54 to 44 — two independents caucus with Democrats — and it's conceivable attendance could be an issue on close votes, especially if Sen. Lindsey Graham, R-S.C., jumps into the race.
But Majority Leader Mitch McConnell, R-Ky., is confident it won't be a problem, telling a Louisville television station in January he thought senators running for president would have "no impact at all on what we do in the Senate."
As advice to this cycle’s crop of candidates, Grassley used the example of former Kansas senator and 1996 Republican presidential candidate Bob Dole, who made it to 99 percent of votes in 1995 and 92 percent in 1996.
"He still ran a good campaign," Grassley said. "He didn't win, but he ran a good campaign and got the nomination."
Dole had one major advantage over the current candidates in that he was the majority leader in 1995 and 1996, giving him the ability to schedule votes. But he voted nearly as often when he unsuccessfully ran for the Republican presidential nomination in 1987 and 1988 as the Senate minority leader — 95 percent and 86 percent, respectively.
Dole also retired in June, 1996 to focus fully on the campaign, potentially saving him from any scheduling conflicts.
Grassley, meanwhile, suggests there are advantages to traveling across Iowa, what is colloquially known as the "full Grassley."
"Don’t just go to Des Moines or Cedar Rapids, get around Iowa a little bit," Grassley said. "Maybe you don’t have to do it like I do it — go to 99 counties 34 years in a row — but [Rick] Santorum did that and I think it made a big difference for him."
The 114th: CQ Roll Call's Guide to the New Congress Get breaking news alerts and more from Roll Call in your inbox or on your iPhone.