U.S. Senate races tighten in key states

WASHINGTON, Oct. 31 (UPI) -- Surges by U.S. Senate candidates in at least two races thought to have been pretty much decided have turned the races into nail-biters, political observers say.

Weakened support for President Obama in Ohio and Pennsylvania could be cutting into leads enjoyed by Democratic Senate candidates and give Republicans Josh Mandel in Ohio and Tom Smith in Pennsylvania a chance to pull ahead in the final days of campaigning, The Hill reported Wednesday.

In Nebraska, attack ads that have aired for months may be helping Democrat Bob Kerrey while forcing Republicans to spend funds for their candidate, Deb Fischer, a strong favorite from the start, political observers said.

While Republicans said they expect Fischer to win next week, GOP operative Karl Rove's American Crossroads just bought $420,000 of advertising time and billionaire Joe Ricketts invested $400,000 in the race, The Hill said.

In Pennsylvania, Sen. Bob Casey Jr. led Republican challenger Smith in every poll, but the margin has grown smaller in the last month, the Washington publication said. GOP groups Restore Our Future and Americans for Job Prosperity pumped more than $3.2 million into the Keystone State in recent days.

In Ohio, Sen. Sherrod Brown has seen his edge over Mandel shrink in recent days, The Hill said. Republican ad spending has topped $15.8 million.