Which Aircraft Do You Think Should Win The Bridge Tanker Contract?

Avoiding total reliance on a single aircraft type; buying an off-the-shelf tanker that's boom and probe & drogue compatible (& thus can also refuel USN & USMC aircraft); that's already an export success worldwide and will thus keep Boeing on their toes to deliver and sustain a fully capable KC-46 fleet at a reasonable cost.
Sounds like a no-brainer (before political considerations and the additional costs of a 2nd integrated logistics & support setup are taken into account)

they've both have had development problems; one however requires you start an entirely new supply chain for an aircraft built by the Europeans, who may cut off your supply if they don't like what war you're involved in. Seems like an easy choice, KC-46 all the way.

Another possible option is to sell KC-135s to private companies which will then contract to provide air refueling to the US military. There are companies, like Omega, which already do this.

This would avoid spending valuable procurement dollars on the production of tankers which will be obsolete before they even leave the assembly line. A better plan would be to bring the KC-X program forward.

The MRTT is a more capable long-range tanker but the KC-46 is too important to Boeing for them to loose.

Considering the KC46 quality issues, I would go with the A330. Newer design and more efficient. Long before the KC46, FedEx offered their MD10-30 aircraft to the AF as a base airframe with the STC add-on boom that could have replaced a number of KC135's saving costs with a more efficient 3 engine aircraft. It could have been a good bridging vehicle.

Without knowing the specific operational requirements for the bridge tanker, I must vote for Other.

FedEx dumped the MD-10 as too dated and non viable (and bought 767s)

The KC-46 is clearly the choice but the RFP language is doing to determine if its a real competition or not.

The A330MRT is more a KC-10 class and how needed the KC-10 is overall vs it ageing out is going to be a factor.

USAF leadership has proven to be totally inept (F-35) and can't find its way so who knows what will come out of this.

After reading the article in the AW&ST June 14-27 issue (Page 59) concerning the Republic of Singapore Air Force (RSAF ) SMART MRTT project capability to operate globally with "both personnel and fighter assets to and from anywhere " IN A SINGLE HOP,

As a virtually 'of the shelf'; (every customer 'needs' that nice to have feature), solution the MRTT has the range and capacity to meet most Pacific theatre requirements. After another eight years service with existing customers it should be thoroughly de-bugged, and have the autonomous refueling capability fully effective.
Whether the USAF can wait that long, or want to buy that many over twenty eight years before going for a design made for purpose is a different question.

For Prost:
1. Yes, they've both had development problems, but the KC-46 is still going through those whilst the A330 MRTT has sorted theirs out.
2. Setting up a 2nd supply chain is an additional cost, but this could be used to drive down overall KC fleet costs through competition (one past example being the 1980s Great Engine War between P&W and GE for F15 & F-16 engines, once the GE F110 was qualified for both airframes).
3. "May cut off your supply" needs challenging:
a. Any USAF buy would require a US-based FACO capability (probably at Airbus Mobile, Alabama). This was a standard requirement of all the KC-45/46 competitions run by USAF over the last 2 decades, and means most of the procurement and support $$$ would stay in the US.
b. A330 standard spares are common worldwide to any airline and a fair percentage of them are sourced from the US anyway. Nothing stopping USAF from setting up a US-based 2nd production line for the few critical military spare parts they consider essential / vulnerable to any action by "the Europeans".
c. Airbus is a commercial company (it has fought very hard over the last 20 years to struggle free of French and German political controls). I'm not clear how "the Europeans" would even decide to impose any sort of spares / support embargo, as you'd have to get at least France & Germany to agree to this - and then run the risk of Airbus saying "No" on commercial grounds. Both France & Germany also rely strongly on US kit, so (at least on the military side) they'd be very aware of potential retaliations.
d. There's no such thing as "the Europeans" as the European Commission does not have the power to decree anything diplomatic, despite what they'd like to think.
e. Finally, to be quite frank (as someone from the east side of the Pond) every time we buy US-sourced kit we have to comply with ITAR and the risk that DoD / State may cut spares & support off at any time, even though we're one of the US's most reliable allies. Works both ways.