– They don't know each other, but Josef Mayerhofer, a construction manager, and Harold Fischer, a retired doctor, have at least two things in common.

Both have always voted for Bavaria's dominant party, the conservative Christian Social Union, a key component of Chancellor Angela Merkel's fragile coalition government.

And come Sunday, when Bavaria votes again, neither will do so this time.

Where they diverge is which parties will get their votes: One will vote left, and the other far right. The issue driving both? Migration.

At any other moment in Germany, a regional election in Bavaria would be, well, a regional election in Bavaria. But in the current uncertain political climate, the vote is being closely watched as a referendum on Merkel's migration policy — and a measure of how much German and European politics are being reshuffled by feelings over migration, by the rise of the far right and by the collapse of the political center.

In Bavaria, that political center has been more conservative and dominant than elsewhere in Germany — and has held out longer. But Bavaria's conservatives, who have governed here with an absolute majority for all but one term since the 1960s, could see their vote share shrivel to below 35 percent on Sunday.

As once loyal voters scatter, seven parties could soon sit in the Bavarian parliament, which would make it one of the most fragmented in the country. Two in particular are poised to benefit: the nativist, Euroskeptic Alternative for Germany, and the pro-refugee, pro-European Greens.

"The days of big-tent politics are over, even in Bavaria," said Heinrich Oberreuter, a veteran political analyst and Bavarian conservative himself. As society has become wealthier, more secular and more individualistic, he said, "people increasingly vote on values, and those values have become polarized."

Three years after more than 1 million migrants started arriving in Germany, a noisy and at times ugly election campaign in Bavaria has crystallized into perhaps the clearest battle of values yet.

Alternative for Germany, which is on course to enter the Bavarian parliament for the first time, with an expected 10 percent of the vote, has received the most attention. But the biggest winner could be the Greens.

On course to double their vote share to 18 percent, this onetime single-issue environmental protest party could become the second-strongest political force in Bavaria — and the only viable coalition partner for the diminished conservatives.

Their Bavarian co-leader, the 33-year-old Katharina Schulze, says she wants to tell a positive story about migration and about Europe.

"People are tired of the hate and fearmongering," she said in a recent interview.

"We are very clearly on the pro-European, pro-liberal democracy side," Schulze said. Alternative for Germany, she said, "is our polar opposite," with all of the other parties "swimming in the middle."

Terrified of Alternative for Germany, which has steadily gained support since the 2015 migrant crisis, Bavaria's conservatives responded by veering sharply to the right themselves — before rowing back somewhat when their poll numbers continued to slide.

It is that sort of thing that persuaded Mayerhofer, after 32 years of supporting the conservatives, to vote Green on Sunday.

Mayerhofer joined the conservatives' youth organization more than three decades ago, when he was 14.

But these days, when Mayer­hofer, 47, hears senior conservatives warn of another wave of migration, or the risk of migrant crime, he says he becomes emotional.

Four Syrian families live in his village and "are perfectly well integrated," he said. Two are his immediate neighbors. "There is nothing Christian in vilifying them," he said.

Or take the police controls the Bavarian conservatives have reinstated at the nearby border with Austria, just over a mile from Mayerhofer's house. "We live at the border; there is no problem," he said.

About 60 miles northeast, in another Bavarian hilltop village near the border, Fischer, 63, is equally dismissive of conservative election maneuvering — but for different reasons.

A lifelong conservative like Mayerhofer, he, too, says he will abandon the Christian Social Union because of the recent influx of migrants — but in his case, Alternative for Germany will get his vote.

When migrants started arriving in 2015 and kept coming in 2016, Fischer thought the conservatives might shut the border, do something — "fix this," as he put it.

Every morning, when he drove into the nearby town of Deggendorf, he passed a home for asylum-seekers. "I would see women with face veils crossing the street with no regard for traffic," he said. He complained that the city was changing and that there were "more and more of them coming."

Both men are somewhat nostalgic for the days when the conservatives still had their confidence, when Bavaria and its future seemed in good hands, when politics was not quite so raw.

Fischer says he can no longer talk politics with some family members without falling out.

"Migration," he said, "has split the country, and it has split Bavaria."