Full disclosure: I am a houndsman, but I do not live in Montana nor plan on hunting in Montana with my hounds.
The biggest argument against this is: I don't have hounds and like spot and stalk so I am against it. This is fair and I get it. Everyone has their jam and wants to keep it the best it can be. But one thing to perhaps consider is Montana is growing more and more liberal and when hunting opportunities get taken away, it is incrementally (see California). They stopped lion hunting with hounds, then lion hunting completely, then even bringing a part of a lion across the state line became illegal, then hunting with hounds for bears, then hunting with hounds for bobcats, then they just tried to get all bear hunting outlawed. They succeeded on all but the last one, but will eventually win because it is California. Then they will start on the next lowest hanging fruit, whatever that is. The goal is outlawing hunting.
When they start this in Montana, and they will because bear hunting is the low hanging fruit because they are cute and anthropomorphized in our society, they won't start by saying, "let's get rid of bear hunting altogether." That is, unless there is already no baiting and hound hunting for them to start with first. Hound hunting as a new method of legal pursuit could be a buffer for that, but won't if it is not there. It is uncommon for hunting opportunities to be added rather than taken away. Consider taking advantage of this while you can. It will at least delay the time between now and when you cannot hunt bears in Montana at all. It took years and a lot of steps in California before hunters realized what was happening and started making a fuss about it to legislatures. Hunters who simply wait until their preferred method or game animal is attacked before they care are not helping the cause.
I do not agree with this whole idea that there will be these giant conflicts with hounds and grizzly bears, as with the idea that somehow Montana legislatures will be saving people's lives by not passing this. Besides that I think it is untrue that grizzlies would be killing hound hunters, the legislature would also be saving lives by outlawing anyone on public land in grizzly country, so let's not go down that line of reasoning because it won't benefit us.
Also, Idaho does not shut down hound hunting in every unit with grizzly bears. This is categorically false and misleading. They shut down some but not all. I know there are grizzly bears in plenty of units where hound hunting for bears is legal. Trail camera pictures do not lie. I think the idea that grizzlies will kill a bunch of hounds is also false, as is the idea that a bunch of grizzly bears will somehow die from hound hunting. I know people whose hounds have run grizzlies inadvertently. I would not call this common, but it is by no means rare in Idaho where people hunt them in places where black and grizzly bears live. It is not a big deal. They bay up and the dogs are either pulled off or shocked off. The accidentally killed grizzly bears are not from hound guys. I also disagree with tiptoeing around anti-hunters in hopes of getting a legalized grizzly season. Hound hunting black bears in Montana will not be a defining issue in that debate. It'll be with whatever judge(s) gets the Idaho and Wyoming cases next. I do not see how hunters really gain by lobbying to prevent an entire method of pursuit from becoming legal with the false hope that because of no hound hunting black bears Montana will somehow get a grizzly season which will produce like 3 tags statewide maybe sometime in the next decade or two.
Wolves kill hounds already. This will not change. They kill way more hounds in the winter because lions and wolves are where the ungulates are, and the ungulates are in a much smaller range in the winter. In Idaho there are many places I simply will not run hounds for lions because of wolves. The probability of an issue is multiplied because the area the deer live in is so small and concentrated, so I play it conservatively and won't hunt some units. Bear hunting is different in respects to wolves killing dogs because the concentrations are diluted because deer and elk start spreading out. Yes, always a chance, but the hound guys know that every time they turn loose so let them make that choice. The hound hunters love their dogs. They are also incredibly valuable to them, monetarily and otherwise. Maybe let them decide risk tolerance for their dogs and themselves.
Another thing you need to consider is that plenty of people are already hunting bears in the spring and fall in Montana with hounds. This is a fact, and these bad apples won't make people like houndsmen more, but the truth is that it does happen. Dogs strike a track from the box and they are turned loose on a "raccoon." Oops, they treed a bear instead. I do not agree with or condone breaking the law intentionally like this even if there is a work around from the letter of the law (how do you prove in court that the houndsman knew it was a bear and not a racoon?) Some are bold enough to actually post pictures of dead bears in Montana with a hound or two in the background with GPS collars on. Guess they were just out walking with their hounds and happened to see a bear and sniped it across the canyon and their walking companions snuck in the picture. Not good and not ok, but the reality. If it was legal it would be more prevalent, but it is still going on in Montana currently and it hasn't ruined spot and stalk from what I am gathering.
If you spot and stalk bears from roads this may impact your hunting at some point or another in the next decade. Hound guys will strike and turn loose from roads. The further in you are, the less of a potential impact. I have spot and stalk hunted bears, baited bears and ran hounds. Others hound hunting has never affected the other two for me yet. Regardless of whether or not it will have an impact, I am of the opinion that increasing hunting opportunity is a good thing, even if it doesn't benefit me the way I would like it to. As for Fin's comment on this bill being brought up continually without success, that may point to the direction that it just will not happen in Montana. As for the comments regarding bear numbers and sustainability in some areas, that is a very valid point that needs to be considered and I know nothing about bear numbers there. Like lions, most treed bears won't be shot, but some will and if an area cannot support varying methods of take without setting quotas, that is really a different debate because you are trading one opportunity (hound hunting) for losing an opportunity (the ability to sustainably hunt bears without the hinderance of a quota system.)
But do consider this: When the day comes that Montana is considering outlawing bear hunting altogether and there is a bill on the table, will the Montana bear hunters be cool with the deer hunters who support outlawing bear hunting because they don't happen to hunt bears themselves? What is happening impacts all hunting, not just your special type of it.