Rasmussen (likely voters, 6/17, 5/19 in parentheses):
Mark Udall (D): 49 (47)
Bob Schaffer (R): 40 (41)
(MoE: ±4%)
It's a small bump, but Udall's lead has moved outside the margin of error. His favorability numbers also are way ahead of Schaffer's (56% very or somewhat favorable for Udall vs. 47% very or somewhat favorable for Schaffer, 35% very or somewhat unfavorable for Udall vs. 45% very or somewhat unfavorable for Schaffer).