Here’s the latest addition to our round-up of polls on this year’s Senate races. Be sure to read our Election 2008 overview of the battle for the Senate. Also, check out our Senate “Races to Watch” chart.

**Colorado:** Democrat Mark Udall is leading Republican Bob Schaffer 47 percent to 41 percent in the race to claim the seat of GOP incumbent Wayne Allard, in a Rasmussen Reports poll conducted May 19. Nine percent are undecided and the margin of error is 4.5 percent. Udall is regarded favorably by 50 percent of voters and unfavorably by 35 percent, compared to a 44 percent favorability rating for Schaffer and a 39 percent unfavorable score.