(CNN) -- Sunday marks six months until Election Day.
Up for grabs this November, the Democrats' 55-45 majority in the Senate. The party's defending 21 of the 36 seats in play, with half of those Democratic-held seats in red or purple states.
And there will be elections for all 435 seats in the House. Democrats need to pick up 17 GOP-held seats to win back control of the chamber, a feat political handicappers say is unlikely considering the shrinking number of competitive congressional districts.
When it comes to governors' races, the GOP's defending 22 of the 36 seats up for grabs in November. And some of them are in states that President Barack Obama carried in 2008 and 2012, such as Pennsylvania, Ohio, Michigan, Wisconsin, Florida, Maine, Nevada and New Mexico.
With the midterm contests just six months away, here's a look at six factors that could influence how Election Day 2014 plays out.
Say what you want about other issues, but the economy remains the top concern of Americans when it comes to their vote.
"The economy is stronger than it's been in a very long time," Obama said at a news conference at the end of last year.
By many metrics, he's right. The stock market has been in record territory again, unemployment's at a five-year low, auto sales are at a seven-year high and the housing sector, which dragged the country into recession five years ago, is rebounding.
But many people just don't feel that good about things. National polling indicates most people don't feel nearly as optimistic about the economy and their personal plight.
And a key economic indicator out earlier this week is helping. Gross domestic product, the broadest measure of economic activity, grew at a 0.1% annual pace in the first quarter of this year. While the numbers are probably just the winter weather effect, they add to the perception that the recovery is tepid. And a sluggish economy prevents Democrats from highlighting the issue in the midterms.
"Because the recovery has been relatively modest, moderate in its strength, there's this psychology among people that it's just not getting better out in America," said CNN Chief Washington Correspondent John King.
The economy remains the top issue on the minds of voters. Economic realities, as well as perceptions, will influence voters in 2014.
October 3 could be a crucial date. That's when the Labor Department releases the September unemployment report, the final jobs numbers before midterm elections. Just as the final jobs report before the 2012 presidential election was in the spotlight, this report will also face a lot of scrutiny.
The one name not on any ballot come November could arguably be the most important person in the midterms. Republicans are trying to frame the elections as a referendum on President Barack Obama, in hopes that the Democratic president serves as a drag on his party.
Obama's approval rating has hovered in the low to mid 40's this year in most non-partisan, live operator, national polling. That's slightly higher than where the President stood in November and early December, when his approval rating was at or near all time lows in many national surveys.
The approval rating is considered one of the best gauges of a president's standing with Americans and of his clout with lawmakers here in Washington. And during a midterm election year, the approval rating is constantly under the national spotlight, as it's considered a key indicator of how the president's political party may fare on Election Day.
Obama's approval rating is slightly better at this time in his presidency than his most recent predecessor, Republican George W. Bush.
"Low approval numbers usually spell bad news for the president's party. George W. Bush's rating was in the low to mid 30's in April of his sixth year and his party lost control of the House and Senate later that year. Richard Nixon got only a 26% approval rating in April of his sixth year and the GOP got hammered in the 1974 midterms," CNN Polling Director Keating Holland said.
"On the other hand, high approval rating don't always help. Ronald Reagan's approval rating was at 62% in April of 1986 and remained that high throughout the year, but his party still lost seats in the House and lost control of the Senate in the 1986 midterms," Holland added.
Keep a close eye on this important indicator. Where the President's approval ratings stand come the autumn will influence the midterm results.
Opposition to the Affordable Care Act, approved in spring 2010 when the Democrats controlled the Senate and the House, was a factor in the Republican wave that November. The GOP took back the House following a historic 63-seat pick up, and trimmed the Democratic majority in the Senate.
The federal health care law, better known as Obamacare, was also a major issue in Obama's 2012 re-election victory over Republican nominee Mitt Romney. The Democrats picked up seats in the Senate and House in that election.
And polling indicates the measure will be in the spotlight again this election, as Republicans make their opposition to the law a centerpiece of their campaign. Just over half of those questioned in the Bloomberg National poll from earlier this year said that candidate opinions about the health care law will be a major issue in deciding how to vote in November. And the most recent surveys indicate that other than the economy, jobs and the deficit, health care is the top concern for voters.
Most recent polling indicates more Americans give a thumbs down to the law than support it. While the numbers have rebounded a bit since last fall's disastrous roll out of the HealthCare.gov website, overall the measure has been unpopular with many Americans dating back to the first debates over the legislation in 2009. But the latest surveys also are clear that more people want to keep rather than scrap the Affordable Care Act.
Democrats defending the overall law tout the popularity of many of the specific provisions.
"If you or someone in your family has a pre-existing condition, you are a winner under the ACA. Ditto if, God forbid, you have an illness or an accident that would have maxed-out your pre-Obamacare coverage limit: the ACA outlaws coverage caps," wrote Democratic strategist Paul Begala in a recent op-ed on CNN.com.
But polling indicates intensity over the measure favors those who oppose it. And in a traditionally low turnout midterm election where getting out a party's base is crucial, the numbers right now appear to aid Republicans.
"In a lower turnout mid-term election like 2014, that gives the GOP a significant initial advantage. Their voters will be easier to motivate and get to the polls than the Democrats," said Neil Newhouse, a top pollster for Romney's 2012 presidential campaign and a co-founder of Public Opinion Strategies.
Keep your eyes on health-care related dates: In late June, the Supreme Court will issue an important ruling on the Affordable Care Act. And in the late summer and early fall, some states will begin to announce how much health insurance premiums will rise in 2015 for policies acquired through the Affordable Care Act. Even though premiums tend to rise every year, big jumps could damage Democrats who defend the health care law.
Income and gender equality
While Republicans think health care is a winning issue with their base, Democrats feel the same way about income and gender equality.
The White House and Democrats in Congress are shining their spotlight on raising the minimum wage and extending long-term unemployment benefits. Both measures face difficult paths to becoming law (as witnessed this week in the Senate), due to push back from Republicans.
Democrats are trying to motivate their base, single women, younger voters, minorities, to vote in the midterms - something they don't do in great numbers compared to the GOP base.
The Democrats' 'equal pay' argument is an effort to change what the election is about. If it is about Obama and the slow economic (jobs) recovery, Democrats are in serious trouble. If it's about equal pay, the minimum wage and similar issues, Democrats can avoid serious damage at the polls. It isn't easy to change the election narrative, but for Democrats in D.C. and around the country, it's certainly worth a try," said Stuart Rothenberg, editor and publisher of the nonpartisan Rothenberg Political Report.
Fight for the GOP
For the third election cycle in a row, we're witnessing a skirmish between grassroots conservatives and the establishment for the future of the Republican Party.
Since the birth of the tea party movement in 2009, primary challenges from the right have produced major headlines and headaches for the GOP and hurt the party's chances of winning back the Senate from the Democrats in the past two election cycles. Candidates backed by the tea party movement and other grassroots conservatives effectively cost the GOP five winnable Senate elections the last two cycles in Nevada, Delaware, Colorado, Indiana and Missouri.
But incumbents and establishment-backed candidates may have the upper hand this time around.
"I don't think we can say that the tea party movement is dead, but there seems to be less enthusiasm among their activists and supporters this year," said Jennifer Duffy, senior editor for the non-partisan Cook Political Report, a top campaign handicapper. "Establishment Republicans and incumbents have learned to run against tea party- backed candidates.
And that could have a big impact come November, boosting the GOP odds.
"When you nominate candidates who have appeal to state-wide electorates, it absolutely improves your chances," Duffy added.
Global hot spots
Call this the wild card.
The crisis in Ukraine has been a headline in the United States for the past two months, with divisions over what the America should do to punish Russia. And debate continues over how involved Washington should get in the bloody three-year civil war in Syria.
Other hot spots such as Iran, North Korea, and Yemen, could also flare at any moment.
Meanwhile, Democrats and Republicans are still arguing about the September 11, 2012, attack in Benghazi that killed the ambassador to Libya and three other Americans.
"Foreign policy rarely matters in midterms, but when it counts, it counts for a whole lot. Remember that on September 10, 2001, we all thought that the 2002 midterms would revolve around mundane issues like stem cell research, and everyone expected the GOP to lose seats," Holland said.