THE BURNED OVER DISTRICT

Republican candidates in a number of important states are finding out that winning a statewide election in most cases involves more than being selected by your party. If you don't have absolute control over voter rolls and paperless voting machines you may well find the majority of voters don't want you.

Republican leaders are increasingly worried that their candidates for governor and Senate are in political trouble across Michigan, Pennsylvania, Minnesota and other states that the party prizes, and that the difficulties could spill into House races that the G.O.P. needs to win in November to keep control of the chamber.

Their concerns also extend to Democratic-leaning states like California, Illinois and Virginia, where top-of-the-ticket Republicans are running well behind in polls — allowing Democrats to focus millions of dollars of spending as well as campaign time and turnout efforts in hotly contested House districts in hopes of knocking off G.O.P. incumbents.

The Republican troubles in these states reflect a confluence of factors: outgoing governors with baggage and nominees with limited charisma and appeal; Democratic advantages in fund-raising and on the key issue of health care; voter intensity fueled by opposition to President Trump; and a rival slate of Democratic candidates, particularly for governor, who are closing the fall race in a strong position.

With polls showing the top Democratic candidates leading in these states, the favorable conditions are important to the party given the Republican edge at the top of the ticket in places like Arizona, Maryland and Massachusetts and their strong chances at winning Democratic-held Senate seats in Missouri and North Dakota, which could enable them to retain or even expand their majority in the Senate.

Republicans are also focusing on winning battlegrounds like Wisconsin, Florida and Ohio, where their nominees for governor are running more evenly against Democrats. But even in Wisconsin, where Gov. Scott Walker, the G.O.P. incumbent, is battling for a third term, President Trump is coming Wednesday to try to shore up the party’s ticket, including its struggling Senate candidate, Leah Vukmir.

“Governor’s races lead the off-year ticket so they work like a big snowplow, clearing the way for the party offices below them,” said Mike Murphy, a Republican strategist. “If you have a weak snowplow, a lot less gets through behind you”

As the G.O.P. struggles particularly in the Midwest, which President Trump sees as perhaps the most crucial part of his base, Michigan offers a vivid illustration of a crucial political dynamic: While control of Congress and the midterm implications for Mr. Trump consume attention, it is the coattails of Democrats at the top of state tickets that could dramatically reshape American politics after 2018.

In Michigan, which the president narrowly carried in 2016, the Democratic nominee for governor, Gretchen Whitmer, has become one of the year’s breakout sensations after cruising in an easier-than-expected primary and establishing a commanding general election lead. On Friday night, she campaigned in this college town with Senator Bernie Sanders to rally young voters — not because she needed help, but because Michigan Democrats now think they could flip as many as four House seats in the state and win other races to loosen the Republicans’ grip on power here.

With a landslide vote, Democrats could also flip the state legislature; restock their bench with up-and-coming politicians; lock in congressional gains by undoing Republican-led gerrymandering; and pass an initiative making it significantly easier to vote by 2020 in a state that broke Democratic hearts two years ago.

Republican style politics thanks to The Orange Humperdoo are showing themselves to be a disaster in preactice, regardless of how good they may sound. And the standard GOP FUD is sounding more and more desperate and that doesn't work on desperate people.