The decision by popular Rep. Mike Rogers (R-Mich.) to retire sparked fresh Democratic optimism Friday about competing for a seat that would otherwise have been out of their reach. But Republicans still have the upper hand there.

A crowded field of candidates could scramble to run for Rogers's seat with less than a month until the filing deadline. Democratic enthusiasm was spurred in part by the lean of the district, which tilts toward Republicans, but not by much. Mitt Romney won 51 percent of the district in the 2012 presidential election, while President Obama carried 48 percent. Obama won 52 percent in that district in 2008.

"Voters in Michigan’s eighth congressional district have shown that this district is competitive – supporting President Obama in 2008 and nearly in 2012 – and they’re hungry for an agenda that puts the middle class first," said Democratic Congressional Campaign Committee Chairman Steve Israel (N.Y.).

In a radio interview Monday, Rogers did not dispute the suggestion that his brother, Bill, a state legislator, might run for the Lansing area seat. In addition to Bill Rogers, Republicans familiar with the district pointed to former state Senate majority leader Mike Bishop (R), former state House speaker Craig DeRoche (R) and Oakland County Sheriff Mike Bouchard (R) as three more possibilities. Another name to watch: Former state GOP chairman Saul Anuzis, who will consider it.

A Democrat familiar with the district pointed to Ingham County Clerk Barb Byrum (D) as a potential candidate. Bynum performed the state's first same-sex marriage ceremony this week, and her mother ran a very competitive campaign against Rogers in 2000.

Potential candidates won't have much time to make up their minds: The filing deadline is April 22.

Republicans are confident they can hold the seat, even without Rogers. They noted that Florida's 13th District, which is more favorable to Democrats, didn't slip into their hands in a recent special election. And in a non-presidential year, it will be difficult for Democrats to ramp turnout and spring an upset in Michigan's 8th District.

"I wish Mike and his family all the best and have every confidence we will elect another Republican leader from this district in November," said National Republican Congressional Committee chairman Rep. Greg Walden (Ore.).

Rogers is the third member of the Wolverine States's congressional delegation to opt for retirement. Sen. Carl Levin (D-Mich.) and Rep. John Dingell (D-Mich.) are also stepping down.