Since it has been about a month I thought a status report would be good.
Republican held seats in jeapardy
AZ Likely opponents Sinema Vs. McSally, Latest polls Sinema +6, Clear lead for Sinema in all polls
AZ2 possible if McCain retires before May 31. After May 31 the AZ governor (R) will appoint a replacement to finish out the term
I expect McCain will hold out if he can so a Republican gets appointed, otherwise Republicans run a real risk of losing both AZ Senate seats in November.
TN Bredesen Vs Blackburn RCP average Bredesen +5, latest pole Bredesen +3, greatest difference +10 Bredesen, clearly breaking for Bredesen
NV Heller Vs Rosen, latest polls Heller +1, Rosen +.4, a true toss-up
TX Cruz Vs. O'Rourke, latest poll Cruz +3, another toss-up, although still being labeled as likely Republican by most prediction services.
MS2 LIkely Opponents in the run-off Hyde-Smith Vs Espy, latest poll Hyde-Smith +6 (but with 22% undecided)
This poll had an essentially equal percent of Republican and Democratic responders, so Espy's best chance would rely on a strong Democratic turnout similar to the recent Alabama senate election. A strong Democratic candidate for governor will also drive Democratic turnout. This one is to early to tell, even if it is considered likely Republican by most services.
The Republicans could lose between 2 and 5 seats based on the current figures. 5 would only happen if there is a lopsided turnout similar to what happen in Alabama.
Democratic held seats in jeopardy
FL Nelson Vs Scott, RCP average Nelson +3.8, latest poll Nelson +4, no polls have shown Scott with a lead
IN Likely Opponents Donnely Vs ?. The Republican primary is May 8, It is too early to get accurate polling for the general.
MO McCaskil Vs Hawley RCP average McCaskil 2.3, latest McCaskil +4, no polls have shown Hawley with a lead
ND Heitkamp Vs. Cramer, Latest poll Heitkamp +3, Heitkamp consistently leading the polling
WV Manchin Vs ?, Primary May 8, Manchin is polling ~50% against all possible opponents with a big lead against all the Republican candidates
MT Tester Vs. ?, primary June 5. All major predictor sites have this as a lean Democratic race
OH Brown Vs Renacci, Brown +13 average of latest two pools. Lean Democrat on all major prediction sites, but so far looks like a safe Democratic seat.
It looks like the Democrats could lose between 0 and 4 seats, with Indiana being the least predictable at this point.
I read an interesting article that looked at the toss-ups in mid term senate races and they always break for one party or the other typically at about an 80% clip. It currently looks like things are breaking in the Democrats favor this time.