Why have unemployment benefits become a battle?

Senate Majority Leader Harry Reid plans a first vote Tuesday morning toward renewing unemployment benefits for about 1.3 million Americans who lost them when they expired at the end of December.

Democrats and President Barack Obama support the extension – which had been scheduled for a vote Monday evening but Reid delayed the vote until Tuesday – while Republicans generally oppose extending those benefits.And with Democrats in control of the Senate and Republicans having a majority in the House, the issue doesn’t seem to be one that will be easy to resolve.

1. The check’s not in the mail

Roughly 1.3 million long-term unemployed were affected when Congress failed to continue a 2008 recession-era federal law providing nearly a year of benefits, paid for by U.S. taxpayers, that kicked in when state jobless benefits ran out. As Gene Sperling, director of the White House’s National Economic Council told CNN’s Candy Crowley on “State of the Union.” “(Monday) is actually the day that 1.3 million Americans will go to the mailbox and find that check missing, the check that they rely on to put food on their table.”

2. New year, old fight

Expect a repeat performance of years past when Democrats and Republicans clashed in often dramatic showdowns rife with fiery rhetoric and lengthy filibusters.

Democrats argue the program is needed to sustain economic recovery and offer a lifeline to those struggling to keep their head above water financially. Republicans counter the benefits are an economic drain and a disincentive to looking for work. The Congressional Budget Office estimates continuing them for another year will cost about $26 billion.

Republican leaders say they would consider extending the benefits but insist that the $26 billion comes from making cuts elsewhere.

Reid said Sunday that the government normally doesn’t have to make “offsets” for emergency funding like these benefits and called the Republican demands “foolishness.”

Hillary Clinton encourages extending benefits for jobless

3.Politics at play

The legislative fights will take place against the backdrop of a midterm election year. Democrats are refocusing on issues relating to economic inequality, which is important to their base.

Many Republicans, including potential 2016 presidential candidate Sen. Rand Paul, R-Kentucky, have long insisted that the Great Recession-era extension of emergency federal benefits deter job-hunting and are unnecessary as the economy rebounds and unemployment declines.

“When you allow people to be on unemployment insurance for 99 weeks, you’re causing them to become part of this perpetual unemployed group in our economy,” Paul said on Fox News last month. “And it really – while it seems good, it actually does a disservice to the people you’re trying to help.”

CNNMoney: Job search: One year and counting

4. White House wades into the fray

The message from the White House on this issue: Bring it on!

In his weekly address over the weekend, President Barack Obama blasted Republicans in Congress who “went home for the holidays and let that lifeline expire.”

“That’s my New Year’s resolution – to do everything I can, every single day, to help make 2014 a year in which more of our citizens can earn their own piece of the American Dream,” Obama said in his address.

5. The honeymoon’s over

The tone set by this first political showdown could foreshadow the tenor of future fights over funding the federal government, raising the debt ceiling, efforts to try and repeal or roll back portions of the President’s signature health care law and the long-postponed fight over immigration reform.

CNN’s Lisa Desjardins contributed to this report.