Nancy Pelosi may lose her train of thought and forget key words more often these days. But Republicans are hoping the 78-year-old House Democrat leader can hang in there at least through this fall’s election. And if fortune smiles on the GOP, future ones too.

This is the fifth straight set of House elections that Republicans have used her as the ultimate liberal bete noire to drive party faithful to the November polls for GOP House candidates. It works.

Pelosi became Speaker in 2006 when Democrats seized control of both chambers in an anti-Bush cycle. But in the first midterm elections of Barack Obama’s terms, Democrats suffered an historic loss of 63 House seats. Like Obama an assiduous fundraiser, Pelosi vowed to take back the House in 2012. But didn’t. Again in 2014. But didn’t. And again in 2016.

After that fourth election defeat, Pelosi faced a leadership challenger from Ohio calling for younger, more open, more regionally diverse leadership. Pelosi won anyway.

Charged by Trump hate, her party need only gain 23 House seats this November to make her Speaker again, unless she succumbs to another, this time successful challenge. A challenge seems likely, however the Nov. 6 results come out.

All three current Democrat leaders are in their late 70s and all from coastal states. An eager freshman class from other areas would seem unlikely to settle without pieces of the leadership pie. Then, there’s the simmering establishment-progressive split among Democrats.

In part to protect themselves from the predictable Republican efforts to tie every Democrat to the 16-term liberal,  San Franciscan, 26 Democratic House candidates have already refused to promise her their leadership vote come December.

That could change, of course, once the election is over. Imagine that.

New York Democrat Rep. Brian Higgins said he’s heard from colleagues worried over the GOP Pelosi ads that they blame for the defeat in Ohio’s special election. “People pretend that (Pelosi) isn’t a problem,” he said. “But it is a problem.”

To counter the GOP strategy this cycle Democrat candidates are attempting to customize their political messages to their individual districts. And persistent questions about a professed loyalty to Pelosi hamper that.

Experts estimate at least one-third of the ads in the Ohio 12th District campaign mentioned her, even more in the closing week. That could be a factor in Democrats’ shrinking lead in generic ballot polling, as our colleague Ed pointed out here yesterday.

She’s Nancy Pelosi and she did not approve those ads.