Some free advice, then.
You can always start with a generic “not enough information” approach. That’ll fly at least until his arraignment. After that, you can fall back on the “innocent until proven guilty” mantra, but be very careful about how you frame it.
Avoid anything that shows more sympathy for the (alleged) perpetrator than the (alleged) victims. Avoid coming across like a man who’s never given a thought to the reality of women’s lives. Avoid an overzealous presumption of innocence: “I can’t believe good old Norm would do this.”
Be absolutely sure to avoid casting aspersions on the (alleged) victims. Nothing about skanks or tramps or lowlifes or entrapment.
Try this on for size:
“It’s premature to form any conclusions. But I am deeply troubled by Sen. McAllister’s arrest. If these charges are true, then he’s not the person I thought he was.”
You can stop there and you’ll be fine. Optional addition:
“If these charges are true, the senator should receive the appropriate punishment under law, and should be removed from the Senate.”
That’s good. Keep it short, keep it clear, and don’t say anything you’ll regret if good old Norm turns out to be guilty.
The Senate is a very hidebound place. And, although there are quite a few women Senators, it still has an aura (or taint, if you prefer) of an old-fashioned men’s club. And frankly, most Senators carry themselves as if they’re slightly different from and superior to the rest of us plebes. Not all, but most.
If McAllister’s arrest might possibly have any positive effect, maybe it’ll deflate some Senatorial egos. It certainly serves as a stark reminder that we’re all human, and you never really know.
Postscript. It’s tempting, as a liberal blogger, to point out the contrast between McAllister’s public moralizing and his (alleged) private behavior. But I’m well aware that conservatives have no monopoly on hypocrisy, sexism, or scumbaggery, so I’ll pass on the temptation.