Democrat Tammy Baldwin still leads Republican Tommy Thompson in Wisconsin's U.S. Senate race according to a poll released Monday.  The news comes even as the same poll found support for President Obama declining.

The firm Public Policy Polling, or PPP, surveyed the same group of Wisconsin voters about both the U.S. Senate race and the race for the White House. It found President Obama's lead over Mitt Romney had shrunk to just two points--a drop of five points from the last time they polled. Baldwin, meanwhile, retained a three point lead. PPP's Tom Jensen said it was the third time in the last month that they'd found Baldwin leading by three or four points, "Thompson certainly has time to make up this deficit right now. But the race is definitely settled into a situation where voters aren't particularly high on him and Baldwin has this persistent, small lead."

Particularly telling, Jensen said, was the fact that those surveyed were evenly split on whether they saw Mitt Romney favorably versus unfavorably, "Thompson, on the other hand, is pretty unpopular. Only 43-percent of voters have a positive opinion of him to 50-percent who see him negatively. So because of that, Baldwin is slightly outrunning Obama."

Jensen calls Wisconsin's U.S. Senate race one of the top three most competitive in the country and a crucial one for Republicans if they want to regain control of the chamber.