The Iron Law of the Twin Cities is that if Minneapolis has something, Saint Paul gets one too (and vice versa). The examples are numerous (arenas, campuses of the University of Minnesota, branches of I-35, chapters of the American Automobile Association, and so on).
In a previous post I posited a Minneapolis Circle Line . Of course Saint Paul would want to get in on the action.

I have drawn two possible fixed route, exclusive(ish) right-of-way transit lines (an Inner Circle and an Outer Circle), along with the already planned Central Corridor. I have not shown other possible lines, presumably radial, that would extend from Saint Paul (one imagines one on 7th Street/Fort Road to the southwest, a streetcar along Grand Avenue, something along Robert Street to the South, something to the west, northeast, and northwest.

The Inner Circle follows the Central Corridor line beginning at Marion Street but continues on University past the Capitol, past Regions Hospitalacross I-35E to Lafayette Road, goes south down Lafayette Road across I-94, and runs behind the proposed St. Paul Saints stadium through Lowertown, meets the Central Corridor again at Union Depot, and then jogs over to Kellogg Boulevard to run past RiverCentre, Xcel Energy Center, the Science Museum, the History Center, near the Cathedral, and up Marion Street back to University Avenue. It would serve re-developable areas near Lafayette road and Marion Street, and major attractions in the city.

The Outer Circle I have broken into two sections for convenience: North and South.
The Outer Circle (north) begins at the Dale Street station on the Central Corridor, runs north to the Pierce Butler route corridor, and goes east parallel the existing railroad tracks, behind the Minnesota Transportation Museum, across I-35E, and then south to University Avenue where it meets the Inner Circle alignment. It serves
The Outer Circle (south) also begins at the Dale Street station, runs south to Summit Avenue (I assume it would share right-of-way with the “Grand Avenue” streetcar should such a thing exist), proceed down Summit Avenue, to Ramsey Street, past United Hospital, serving the West Seventh area. It would turn south on Smith Avenue, cross the Mississippi River, to George Street, serving the West Side. It would proceed East on George Street to Cesar Chavez Street, and then Ada Street. It would cross the Lafayette Freeway and run along the edge of the St. Paul Airport. Here is the expensive part: a new river crossing would need to be constructed to get from the south to the north banks of the Mississippi River. The line would climb up Mounds Boulevard, serving Dayton’s Bluff and Metropolitan State University, and then run southeast along 7th Street/Fort Road, to the Inner Circle.

Rings make the most sense in the context of existing (or future) radials, allowing cross-traffic in cities and shortening travel times for those not going downtown. Given that St. Paul CBD has about 3% of the region’s employment (~40,000 jobs) (1990 statistics), new systems should not focus exclusively on such a small market, but should better help travelers reach diverse destinations across the city.