Democrats are pumping more money into competitive House races to protect four incumbents in Minnesota, Illinois and New York.

The party is increasing its spending on two Republican-held seats in Nebraska and Iowa that represent some of the Democrats' best chances to win on GOP turf.

The national party is cutting back on spending in California, Pennsylvania and Michigan as opportunities for gains have diminished four weeks to midterm elections.

Republicans are expected to pad their majority on Nov. 4 as President Barack Obama's low approval ratings in the sixth year of his tenure remain a drag on Democrats. The Democratic Congressional Campaign Committee has outpaced its GOP counterpart in fundraising, and the party has increased its advertising spending $12.5 million on top of its initial $43.5 million ad buy.