Use video! It's not that hard and it reaches people in ways that no other technology can! It's a great audience builder.
You already know the audience you can reach via conference calls and tele-town halls. And you know how fast you can build your audience from a standing start. Add video, and you can quickly expand that audience reach to 2 or 3 times what you had before. Provide good, interesting content, and you can continue building your audience far beyond that.
There are definitely situations where you need to hire a full crew as in the accompanying photo, but today it's much rarer, and having a small budget does NOT mean you should have small ambitions for employing video wisely and effectively in your campaign.
Especially in a world of web sites, social media and mass emails, appearing on video restores the human element that's missing from our usual i-communications channels. You want to restore that human element, right?? Adding that important human element of respect for the voter or consumer locks your people in -- it builds enthusiasm and provokes action. Trump did that. Hillary didnt. 'Nuff said.
Pervasive video appearances help you do it.
Almost every campaign or business has tried posting or sharing a short smart phone video on Youtube or Facebook. So easy! Now that you've succeeded at that, only a couple of small items are needed to assure high production values if you decide to leverage that video into more productive (and more widely attended!) conference calls and tele-town halls.
I'll just mention some points just once in passing, but they are extremely important: use camera mounts (usually a tripod - a good table-top example is here) for steady shots and use a quality microphone (good examples here and here) for great audio - neither are expensive, but they add to quality video far, far out of proportion to their cost. Use these tools even if you are shooting with a smart phone!
Another point I'll mention in passing, but still supremely important, is to seek tools that will allow you to embed your conference call or tele-town hall in your own web page. If your live video event is successful and you quickly grow your audience as you hope, then why send members of your audience to someone else's web site to participate?? Most candidates and businesses instantly recognize the merit of bringing their audience to their own web property to participate. It makes each member of your audience more likely to return to your web site later, and for people who had to miss the event, but want to see the recording, bringing them to your own web property is a big win for getting other elements of your message into their minds as they surf around your site (you do have that side or top menu to tempt them to your other pages. right??).
So now back to the main story (now that we've established that you are going to have steady camera mounts - even for a phone - and good audio and all your great video is going to be presented on your own web site)...
Many campaigns and companies are highly skeptical of video shot on phones, but the fact is perfectly exceptional content can be produced even from old phones. The film Tangerine was a breakout favorite at Sundance (free if you are a Netflix subscriber). Other acclaimed shorts include Night Fishing, Romance in NYC, Framed, The Editor, and Dragon Bourne. I said old phones above, didn't I? The above were shot on devices like iPhones 5 and 6. iPhone 8 and X are the latest phones. Android phones can meet and exceed iPhone video quality, too.