MILWAUKEE - With Democrats aiming to keep control of the US Senate and Republicans hoping to wrest it away from them as well as hang onto their majority in the House of Representatives, four states will hold primary votes on Tuesday to choose their party's candidates to run for Congress in the November 6 election.
Voters in Wisconsin and Connecticut will pick candidates for open seats being vacated by retiring Senators Herb Kohl and Joseph Lieberman. Kohl is a Democrat, and Lieberman is an independent but caucuses with the Democrats.
In Florida, the two-term Democratic Senator Bill Nelson is facing a tough primary challenge, while Republicans are going to the polls to pick a challenger.
Minnesota Senator Amy Klochubar, a Democrat, is expected to survive a primary challenge on Tuesday, while several Republican hopefuls are vying for the chance to run against her.