On the Republican side in particular, the recent violence shifted the contours of the contest.
GOP candidate Gabriel Gomez, a former Navy SEAL, finished running the marathon minutes before the bombs exploded along the finish line, killing three and injuring more than 260.
Like other candidates, Gomez immediately pulled television ads off the air and suspended campaign activities. He said he was focused on being respectful as he eased back into campaigning the following weekend.
Republican candidate Dan Winslow, a former judge and chief legal counsel under former Gov. Mitt Romney, said the entire GOP field has experience with national security.
“We’ve got a Navy SEAL, a former prosecutor and a former judge all in the field for Republicans,” Winslow said. “I think we all have our own credentials. The key is, Who’s got the better ideas? Who’s got the better electability in June?”