In politics, there are tricks aplenty that candidates use to avoid high-profile debates. One can do as Ted Kennedy did in 2006 and accept a single debate on a well-regarded but relatively low-profile media outlet like New England Cable News. He or she can agree to debate only on a night when more enticing events loom, or insist on debates that occur before voters are fully focused on the race. Massachusetts voters shouldn’t let either of the candidates in the US Senate race get away with any of them.