(CNN) - New polls in four southern states that could determine whether the Democrats keep control of the Senate in this November's midterm elections indicate close contests.
And according to the New York Times Upshot/Kaiser Family Foundation surveys, released Wednesday, President Barack Obama's approval ratings are in the low 30's in two of those states and hovering at or just above the 40% mark in the other two states. Republicans are trying to frame the midterm contests as a referendum on the President and on his federal health care law, better known as Obamacare.
In North Carolina, the poll indicates first-term Democratic Sen. Kay Hagan is all tied up with state House Speaker Thom Tillis in a hypothetical general election match-up. Hagan's two-point 42%-40% margin is within the survey's sampling error. Tillis is considered the front-runner right now in the May 6 GOP Senate primary. Hagan also holds a two-point margin (41%-39%) over Republican candidate Greg Brannon, who's favored by many conservatives, in another potential November showdown.
The poll indicates North Carolina voters are split at 44% on whether they approve or disapprove of the job Hagan's doing in the Senate. The President's approval rating in the state stands at 41%, according to the survey. Presidential approval ratings are considered an important indicator in midterm elections.
McConnell deadlocked with Grimes
In Kentucky – one of only two states right now where the Democrats hope to go on offense – the poll suggests that Senate Republican Leader Mitch McConnell's basically deadlocked with Democrat Alison Lundergan Grimes. According to the poll, 44% of registered voters in Kentucky say they'd vote for the five-term senator in the general election, with 43% saying they'd back Grimes, Kentucky's secretary of state.
The poll indicates McConnell's approval/disapproval rating (40%-52%) is underwater with Bluegrass State voters. But only a third of Kentucky voters give Obama a thumbs-up on the job he's doing as President, which helps McConnell's campaign, as it tries to tie Grimes to Obama.
McConnell first needs to get by a primary challenge from businessman Matt Bevin, who enjoys the support of tea party groups and some Washington-based conservative organizations. McConnell's considered the overwhelming favorite in Kentucky's May GOP Senate primary. But if Bevin pulls off a huge upset, the poll indicates Grimes has a 41%-36% advantage over Bevin in a hypothetical general election match-up.
Pryor on top in another poll
The New York Times Upshot/Kaiser Family Foundation survey is the latest in a series of recent polls to indicate Sen. Mark Pryor of Arkansas is ahead of freshman Rep. Tom Cotton, his GOP challenger. According to the new survey, Pryor holds a 10-point 46%-36% lead over Cotton.
The two-term Democratic senator's approval/disapproval ratings stand at 47%-38%. But only 32% of Arkansas voters say they approve of the job Obama's doing as President.
Landrieu below 50% mark
Forty-two percent of Louisiana voters say they back Democratic Sen. Mary Landrieu, who's running this year for a fourth term in office. The poll indicates 18% support Rep. Bill Cassidy, the Republican front-runner, with two other GOP candidates in single digits. Louisiana has no primary and all the candidates appear on the November ballot. If no one cracks 50% of the vote, the top two finishers compete in a runoff in December.
Landrieu has a 49%-45% approval/disapproval rating, with Obama's approval rating hovering right around the 40% mark.
Democrats hold a 55-45 majority in the Senate (53 Democrats and two independents who caucus with the party), but are defending 21 of the 36 seats up in November, with half of those Democratic-held seats in red or purple states, like Arkansas, Louisiana and North Carolina. Kentucky and Georgia are considered the only two states right now where Democrats have a chance of picking up a GOP-held seat.
The New York Times Upshot/Kaiser Family Foundation poll was conducted April 8-15, with 857 registered voters in Arkansas, 891 registered voters in Kentucky, 946 registered voters in Louisiana, and 900 registered voters in North Carolina, questioned by telephone. The survey's sampling error for registered voters is plus or minus four percentage points.
CNN Political Editor Paul Steinhauser contributed to this report