From the history (reported to the committed by Bonnie Cullison), this type of bill has previously been passed twice by the House. It was the Senate which had blocked it.
When we were up at lobby day (in February), our state senator was concerned that the senate committee would vote down the bill, 5-6, again killing it. This time, though, the committee voted 8-3 in favor, then the senate as a whole 32-15 in favor. It no doubt helped that the governor is a supporter of the bill, and came out to the lobby day speaking in favor of it (this is the 3rd or 4th lobby day, first time a governor has come. The Lt. Governor testified to the House committee the day my wife and I did, also I think unusual.)
I don't know if the bill will pass out of the House committee this year. But two things I'm confident about:
1) The chances improve as more people contact their House representatives
2) If it doesn't pass this year, we (my wife and I, and a number of the people we've spoken with at the events) will be back next year and the year after, and after, until it does pass.
Different matter I'm even more confident about: If it doesn't pass for the state, my wife and I will start working on Prince George's county -- the largest county with no such equality bill yet in Maryland. I'll be back here then, asking for folks who can work with us. By way of our prior activity, I've got some confidence that we can make some things happen. We did some door to door work for marriage equality in 2012, which did pass in the state. Didn't get a majority in PG, but was much closer than many had expected. (Granted the major shift there was due to Obama, rather than us door to door folks. Still.) 'churches' are a big concern in this. But I already know some which will work with us, rather than against.
PM are welcome.