This will bring out the haters as usual, but with all it's faults CAHSR has potential as a new trunk line for interregional travel - which is the state's business. It's getting hard to do anything worthwhile in terms of expanding highways, and since the MPOs (by California law) pretty much control all of the highway money (even the interregional highway funds programmed by the state have to run through the regional transportation plans for federal regulatory reasons) that won't change anytime soon. There's still a (slight) separation between interregional rail and local transit though.

I see the LA-BA line currently in the works as a starter line. But only a starter, and incapable on its own of making a profit. And as a practical matter a round trip (6-8 hours) will consume a crew-day so there won't be much work time left over for logical extended runs. So how best to arrange follow-one work?

I would suggest a Southern California Division: San Diego-Ontario-LAUS-LAX, with possible branches to Anaheim/Irvine (John Wayne airport?), Palm Springs, and possibly connection with XpressWest to LAS if they decide to go through Cajon Pass (unlikely - their only stated plan so far was to co-route with Hwy 138 reconstruction between Victorville and Palmdale then share track with CAHSR or Metrolink into LA, and punching through Cajon would be a serious job even if tunneling is minimized by steep grades). The SD-LAX line would be slower than mainline HSR due to grades/alignment (fitting into a built-up area) and stops, so a crew-day would likely only produce 2 round trips. A plus would be connection to 3 important airports (LAX, SAN, and ONT) and possibly a third (SNA); arguably even the mainline LA-BA trains should extend (some at least) to LAX. Being SoCal-exclusive, this line might be able to tap some of the transit and local-improvement programs that pop up there. Of course, there would be competition for those local funds from LOSSAN improvements which are also needed and ongoing.

Then there's NorCal. The system's not complete without some kind of higher-speed (at least) loop connecting the main line at San Jose with Oakland, Sacramento, then back down to Merced, and possibly less-than HSR branches to other NorCal points. The current 3-hour tour between San Jose and Sac is just too long, but improving it much on UP tracks just isn't going to happen. If you're spending that kind of money, then why not drop another tube in the Bay so HSR can get out of town and head east? Oh yes - the Sacramento terminal should be SMF, not just downtown Sac.

As you might guess, I think connecting the airports is at least as important as connecting the downtowns. The Smart Growth (downtown-density faction) group doesn't like that, but it's practical. HSR connecting airports would cut down if not eliminate short-distance air travel, improving GHG emissions significantly as well as reliability. For longer trips, where would you rather leave your car (which will still be needed at most HSR stations especially for multi-day trips) if not at an airport where there are convenient long-term lots? And the airports would get to keep their parking income and get a cut of the HSR fare too - which they would like.

Anyway, the job isn't finished even if the "starter line" between SF and LA gets done. To be a meaningful addition to the transportation system, you need more. As with our freeways, I fully expect the job to take 100 years.