The latest McClatchy-Marist poll shows Ken Buck inching ahead of Sen. Michael Bennet by four points, while in the gubernatorial race Tom Tancredo is keeping it close to Denver Mayor John Hickenlooper by the same margin:

In Colorado, Republican Ken Buck leads Democratic Sen. Michael Bennet, 49 percent to 45 percent. […]
Bennet is ahead by nearly 2 to 1 in Denver, but trails in the rest of the state.
Of those who think the worst economic news is yet to come, 69 percent back Buck. Of those who think the worst is behind them, 68 percent back Bennet.
Of the 40 percent who approve of Obama’s performance, 95 percent back Bennet. Of the 55 percent who disapprove of Obama, 87 percent support Buck.
615 likely voters were surveyed. The margin of error is plus or minus 4 percentage points.